1/* 2** 2001-09-15 3** 4** The author disclaims copyright to this source code. In place of 5** a legal notice, here is a blessing: 6** 7** May you do good and not evil. 8** May you find forgiveness for yourself and forgive others. 9** May you share freely, never taking more than you give. 10** 11************************************************************************* 12** This header file defines the interface that the SQLite library 13** presents to client programs. If a C-function, structure, datatype, 14** or constant definition does not appear in this file, then it is 15** not a published API of SQLite, is subject to change without 16** notice, and should not be referenced by programs that use SQLite. 17** 18** Some of the definitions that are in this file are marked as 19** "experimental". Experimental interfaces are normally new 20** features recently added to SQLite. We do not anticipate changes 21** to experimental interfaces but reserve the right to make minor changes 22** if experience from use "in the wild" suggest such changes are prudent. 23** 24** The official C-language API documentation for SQLite is derived 25** from comments in this file. This file is the authoritative source 26** on how SQLite interfaces are supposed to operate. 27** 28** The name of this file under configuration management is "sqlite.h.in". 29** The makefile makes some minor changes to this file (such as inserting 30** the version number) and changes its name to "sqlite3.h" as 31** part of the build process. 32*/ 33#ifndef SQLITE3_H 34#define SQLITE3_H 35#include <stdarg.h> /* Needed for the definition of va_list */ 36 37/* 38** Make sure we can call this stuff from C++. 39*/ 40#ifdef __cplusplus 41extern "C" { 42#endif 43 44 45/* 46** Facilitate override of interface linkage and calling conventions. 47** Be aware that these macros may not be used within this particular 48** translation of the amalgamation and its associated header file. 49** 50** The SQLITE_EXTERN and SQLITE_API macros are used to instruct the 51** compiler that the target identifier should have external linkage. 52** 53** The SQLITE_CDECL macro is used to set the calling convention for 54** public functions that accept a variable number of arguments. 55** 56** The SQLITE_APICALL macro is used to set the calling convention for 57** public functions that accept a fixed number of arguments. 58** 59** The SQLITE_STDCALL macro is no longer used and is now deprecated. 60** 61** The SQLITE_CALLBACK macro is used to set the calling convention for 62** function pointers. 63** 64** The SQLITE_SYSAPI macro is used to set the calling convention for 65** functions provided by the operating system. 66** 67** Currently, the SQLITE_CDECL, SQLITE_APICALL, SQLITE_CALLBACK, and 68** SQLITE_SYSAPI macros are used only when building for environments 69** that require non-default calling conventions. 70*/ 71#ifndef SQLITE_EXTERN 72# define SQLITE_EXTERN extern 73#endif 74#ifndef SQLITE_API 75# define SQLITE_API 76#endif 77#ifndef SQLITE_CDECL 78# define SQLITE_CDECL 79#endif 80#ifndef SQLITE_APICALL 81# define SQLITE_APICALL 82#endif 83#ifndef SQLITE_STDCALL 84# define SQLITE_STDCALL SQLITE_APICALL 85#endif 86#ifndef SQLITE_CALLBACK 87# define SQLITE_CALLBACK 88#endif 89#ifndef SQLITE_SYSAPI 90# define SQLITE_SYSAPI 91#endif 92 93/* 94** These no-op macros are used in front of interfaces to mark those 95** interfaces as either deprecated or experimental. New applications 96** should not use deprecated interfaces - they are supported for backwards 97** compatibility only. Application writers should be aware that 98** experimental interfaces are subject to change in point releases. 99** 100** These macros used to resolve to various kinds of compiler magic that 101** would generate warning messages when they were used. But that 102** compiler magic ended up generating such a flurry of bug reports 103** that we have taken it all out and gone back to using simple 104** noop macros. 105*/ 106#define SQLITE_DEPRECATED 107#define SQLITE_EXPERIMENTAL 108 109/* 110** Ensure these symbols were not defined by some previous header file. 111*/ 112#ifdef SQLITE_VERSION 113# undef SQLITE_VERSION 114#endif 115#ifdef SQLITE_VERSION_NUMBER 116# undef SQLITE_VERSION_NUMBER 117#endif 118 119/* 120** CAPI3REF: Compile-Time Library Version Numbers 121** 122** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 123** evaluates to a string literal that is the SQLite version in the 124** format "X.Y.Z" where X is the major version number (always 3 for 125** SQLite3) and Y is the minor version number and Z is the release number.)^ 126** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 127** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 128** numbers used in [SQLITE_VERSION].)^ 129** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 130** be larger than the release from which it is derived. Either Y will 131** be held constant and Z will be incremented or else Y will be incremented 132** and Z will be reset to zero. 133** 134** Since [version 3.6.18] ([dateof:3.6.18]), 135** SQLite source code has been stored in the 136** <a href="http://www.fossil-scm.org/">Fossil configuration management 137** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 138** a string which identifies a particular check-in of SQLite 139** within its configuration management system. ^The SQLITE_SOURCE_ID 140** string contains the date and time of the check-in (UTC) and a SHA1 141** or SHA3-256 hash of the entire source tree. If the source code has 142** been edited in any way since it was last checked in, then the last 143** four hexadecimal digits of the hash may be modified. 144** 145** See also: [sqlite3_libversion()], 146** [sqlite3_libversion_number()], [sqlite3_sourceid()], 147** [sqlite_version()] and [sqlite_source_id()]. 148*/ 149#define SQLITE_VERSION "3.40.1" 150#define SQLITE_VERSION_NUMBER 3040001 151#define SQLITE_SOURCE_ID "2022-12-28 14:03:47 df5c253c0b3dd24916e4ec7cf77d3db5294cc9fd45ae7b9c5e82ad8197f38a24" 152 153/* 154** CAPI3REF: Run-Time Library Version Numbers 155** KEYWORDS: sqlite3_version sqlite3_sourceid 156** 157** These interfaces provide the same information as the [SQLITE_VERSION], 158** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 159** but are associated with the library instead of the header file. ^(Cautious 160** programmers might include assert() statements in their application to 161** verify that values returned by these interfaces match the macros in 162** the header, and thus ensure that the application is 163** compiled with matching library and header files. 164** 165** <blockquote><pre> 166** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 167** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 ); 168** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 169** </pre></blockquote>)^ 170** 171** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 172** macro. ^The sqlite3_libversion() function returns a pointer to the 173** to the sqlite3_version[] string constant. The sqlite3_libversion() 174** function is provided for use in DLLs since DLL users usually do not have 175** direct access to string constants within the DLL. ^The 176** sqlite3_libversion_number() function returns an integer equal to 177** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns 178** a pointer to a string constant whose value is the same as the 179** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built 180** using an edited copy of [the amalgamation], then the last four characters 181** of the hash might be different from [SQLITE_SOURCE_ID].)^ 182** 183** See also: [sqlite_version()] and [sqlite_source_id()]. 184*/ 185SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; 186SQLITE_API const char *sqlite3_libversion(void); 187SQLITE_API const char *sqlite3_sourceid(void); 188SQLITE_API int sqlite3_libversion_number(void); 189 190/* 191** CAPI3REF: Run-Time Library Compilation Options Diagnostics 192** 193** ^The sqlite3_compileoption_used() function returns 0 or 1 194** indicating whether the specified option was defined at 195** compile time. ^The SQLITE_ prefix may be omitted from the 196** option name passed to sqlite3_compileoption_used(). 197** 198** ^The sqlite3_compileoption_get() function allows iterating 199** over the list of options that were defined at compile time by 200** returning the N-th compile time option string. ^If N is out of range, 201** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 202** prefix is omitted from any strings returned by 203** sqlite3_compileoption_get(). 204** 205** ^Support for the diagnostic functions sqlite3_compileoption_used() 206** and sqlite3_compileoption_get() may be omitted by specifying the 207** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 208** 209** See also: SQL functions [sqlite_compileoption_used()] and 210** [sqlite_compileoption_get()] and the [compile_options pragma]. 211*/ 212#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 213SQLITE_API int sqlite3_compileoption_used(const char *zOptName); 214SQLITE_API const char *sqlite3_compileoption_get(int N); 215#else 216# define sqlite3_compileoption_used(X) 0 217# define sqlite3_compileoption_get(X) ((void*)0) 218#endif 219 220/* 221** CAPI3REF: Test To See If The Library Is Threadsafe 222** 223** ^The sqlite3_threadsafe() function returns zero if and only if 224** SQLite was compiled with mutexing code omitted due to the 225** [SQLITE_THREADSAFE] compile-time option being set to 0. 226** 227** SQLite can be compiled with or without mutexes. When 228** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 229** are enabled and SQLite is threadsafe. When the 230** [SQLITE_THREADSAFE] macro is 0, 231** the mutexes are omitted. Without the mutexes, it is not safe 232** to use SQLite concurrently from more than one thread. 233** 234** Enabling mutexes incurs a measurable performance penalty. 235** So if speed is of utmost importance, it makes sense to disable 236** the mutexes. But for maximum safety, mutexes should be enabled. 237** ^The default behavior is for mutexes to be enabled. 238** 239** This interface can be used by an application to make sure that the 240** version of SQLite that it is linking against was compiled with 241** the desired setting of the [SQLITE_THREADSAFE] macro. 242** 243** This interface only reports on the compile-time mutex setting 244** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 245** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 246** can be fully or partially disabled using a call to [sqlite3_config()] 247** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 248** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 249** sqlite3_threadsafe() function shows only the compile-time setting of 250** thread safety, not any run-time changes to that setting made by 251** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 252** is unchanged by calls to sqlite3_config().)^ 253** 254** See the [threading mode] documentation for additional information. 255*/ 256SQLITE_API int sqlite3_threadsafe(void); 257 258/* 259** CAPI3REF: Database Connection Handle 260** KEYWORDS: {database connection} {database connections} 261** 262** Each open SQLite database is represented by a pointer to an instance of 263** the opaque structure named "sqlite3". It is useful to think of an sqlite3 264** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 265** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 266** and [sqlite3_close_v2()] are its destructors. There are many other 267** interfaces (such as 268** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 269** [sqlite3_busy_timeout()] to name but three) that are methods on an 270** sqlite3 object. 271*/ 272typedef struct sqlite3 sqlite3; 273 274/* 275** CAPI3REF: 64-Bit Integer Types 276** KEYWORDS: sqlite_int64 sqlite_uint64 277** 278** Because there is no cross-platform way to specify 64-bit integer types 279** SQLite includes typedefs for 64-bit signed and unsigned integers. 280** 281** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 282** The sqlite_int64 and sqlite_uint64 types are supported for backwards 283** compatibility only. 284** 285** ^The sqlite3_int64 and sqlite_int64 types can store integer values 286** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 287** sqlite3_uint64 and sqlite_uint64 types can store integer values 288** between 0 and +18446744073709551615 inclusive. 289*/ 290#ifdef SQLITE_INT64_TYPE 291 typedef SQLITE_INT64_TYPE sqlite_int64; 292# ifdef SQLITE_UINT64_TYPE 293 typedef SQLITE_UINT64_TYPE sqlite_uint64; 294# else 295 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 296# endif 297#elif defined(_MSC_VER) || defined(__BORLANDC__) 298 typedef __int64 sqlite_int64; 299 typedef unsigned __int64 sqlite_uint64; 300#else 301 typedef long long int sqlite_int64; 302 typedef unsigned long long int sqlite_uint64; 303#endif 304typedef sqlite_int64 sqlite3_int64; 305typedef sqlite_uint64 sqlite3_uint64; 306 307/* 308** If compiling for a processor that lacks floating point support, 309** substitute integer for floating-point. 310*/ 311#ifdef SQLITE_OMIT_FLOATING_POINT 312# define double sqlite3_int64 313#endif 314 315/* 316** CAPI3REF: Closing A Database Connection 317** DESTRUCTOR: sqlite3 318** 319** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 320** for the [sqlite3] object. 321** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 322** the [sqlite3] object is successfully destroyed and all associated 323** resources are deallocated. 324** 325** Ideally, applications should [sqlite3_finalize | finalize] all 326** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and 327** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 328** with the [sqlite3] object prior to attempting to close the object. 329** ^If the database connection is associated with unfinalized prepared 330** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then 331** sqlite3_close() will leave the database connection open and return 332** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared 333** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups, 334** it returns [SQLITE_OK] regardless, but instead of deallocating the database 335** connection immediately, it marks the database connection as an unusable 336** "zombie" and makes arrangements to automatically deallocate the database 337** connection after all prepared statements are finalized, all BLOB handles 338** are closed, and all backups have finished. The sqlite3_close_v2() interface 339** is intended for use with host languages that are garbage collected, and 340** where the order in which destructors are called is arbitrary. 341** 342** ^If an [sqlite3] object is destroyed while a transaction is open, 343** the transaction is automatically rolled back. 344** 345** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 346** must be either a NULL 347** pointer or an [sqlite3] object pointer obtained 348** from [sqlite3_open()], [sqlite3_open16()], or 349** [sqlite3_open_v2()], and not previously closed. 350** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 351** argument is a harmless no-op. 352*/ 353SQLITE_API int sqlite3_close(sqlite3*); 354SQLITE_API int sqlite3_close_v2(sqlite3*); 355 356/* 357** The type for a callback function. 358** This is legacy and deprecated. It is included for historical 359** compatibility and is not documented. 360*/ 361typedef int (*sqlite3_callback)(void*,int,char**, char**); 362 363/* 364** CAPI3REF: One-Step Query Execution Interface 365** METHOD: sqlite3 366** 367** The sqlite3_exec() interface is a convenience wrapper around 368** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 369** that allows an application to run multiple statements of SQL 370** without having to use a lot of C code. 371** 372** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 373** semicolon-separate SQL statements passed into its 2nd argument, 374** in the context of the [database connection] passed in as its 1st 375** argument. ^If the callback function of the 3rd argument to 376** sqlite3_exec() is not NULL, then it is invoked for each result row 377** coming out of the evaluated SQL statements. ^The 4th argument to 378** sqlite3_exec() is relayed through to the 1st argument of each 379** callback invocation. ^If the callback pointer to sqlite3_exec() 380** is NULL, then no callback is ever invoked and result rows are 381** ignored. 382** 383** ^If an error occurs while evaluating the SQL statements passed into 384** sqlite3_exec(), then execution of the current statement stops and 385** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 386** is not NULL then any error message is written into memory obtained 387** from [sqlite3_malloc()] and passed back through the 5th parameter. 388** To avoid memory leaks, the application should invoke [sqlite3_free()] 389** on error message strings returned through the 5th parameter of 390** sqlite3_exec() after the error message string is no longer needed. 391** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 392** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 393** NULL before returning. 394** 395** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 396** routine returns SQLITE_ABORT without invoking the callback again and 397** without running any subsequent SQL statements. 398** 399** ^The 2nd argument to the sqlite3_exec() callback function is the 400** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 401** callback is an array of pointers to strings obtained as if from 402** [sqlite3_column_text()], one for each column. ^If an element of a 403** result row is NULL then the corresponding string pointer for the 404** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 405** sqlite3_exec() callback is an array of pointers to strings where each 406** entry represents the name of corresponding result column as obtained 407** from [sqlite3_column_name()]. 408** 409** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 410** to an empty string, or a pointer that contains only whitespace and/or 411** SQL comments, then no SQL statements are evaluated and the database 412** is not changed. 413** 414** Restrictions: 415** 416** <ul> 417** <li> The application must ensure that the 1st parameter to sqlite3_exec() 418** is a valid and open [database connection]. 419** <li> The application must not close the [database connection] specified by 420** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 421** <li> The application must not modify the SQL statement text passed into 422** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 423** </ul> 424*/ 425SQLITE_API int sqlite3_exec( 426 sqlite3*, /* An open database */ 427 const char *sql, /* SQL to be evaluated */ 428 int (*callback)(void*,int,char**,char**), /* Callback function */ 429 void *, /* 1st argument to callback */ 430 char **errmsg /* Error msg written here */ 431); 432 433/* 434** CAPI3REF: Result Codes 435** KEYWORDS: {result code definitions} 436** 437** Many SQLite functions return an integer result code from the set shown 438** here in order to indicate success or failure. 439** 440** New error codes may be added in future versions of SQLite. 441** 442** See also: [extended result code definitions] 443*/ 444#define SQLITE_OK 0 /* Successful result */ 445/* beginning-of-error-codes */ 446#define SQLITE_ERROR 1 /* Generic error */ 447#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 448#define SQLITE_PERM 3 /* Access permission denied */ 449#define SQLITE_ABORT 4 /* Callback routine requested an abort */ 450#define SQLITE_BUSY 5 /* The database file is locked */ 451#define SQLITE_LOCKED 6 /* A table in the database is locked */ 452#define SQLITE_NOMEM 7 /* A malloc() failed */ 453#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 454#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 455#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 456#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 457#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 458#define SQLITE_FULL 13 /* Insertion failed because database is full */ 459#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 460#define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 461#define SQLITE_EMPTY 16 /* Internal use only */ 462#define SQLITE_SCHEMA 17 /* The database schema changed */ 463#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 464#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 465#define SQLITE_MISMATCH 20 /* Data type mismatch */ 466#define SQLITE_MISUSE 21 /* Library used incorrectly */ 467#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 468#define SQLITE_AUTH 23 /* Authorization denied */ 469#define SQLITE_FORMAT 24 /* Not used */ 470#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 471#define SQLITE_NOTADB 26 /* File opened that is not a database file */ 472#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 473#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 474#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 475#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 476/* end-of-error-codes */ 477 478/* 479** CAPI3REF: Extended Result Codes 480** KEYWORDS: {extended result code definitions} 481** 482** In its default configuration, SQLite API routines return one of 30 integer 483** [result codes]. However, experience has shown that many of 484** these result codes are too coarse-grained. They do not provide as 485** much information about problems as programmers might like. In an effort to 486** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 487** and later) include 488** support for additional result codes that provide more detailed information 489** about errors. These [extended result codes] are enabled or disabled 490** on a per database connection basis using the 491** [sqlite3_extended_result_codes()] API. Or, the extended code for 492** the most recent error can be obtained using 493** [sqlite3_extended_errcode()]. 494*/ 495#define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8)) 496#define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8)) 497#define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8)) 498#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 499#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 500#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 501#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 502#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 503#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 504#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 505#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 506#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 507#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 508#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 509#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 510#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 511#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 512#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 513#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 514#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 515#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 516#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 517#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 518#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 519#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 520#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 521#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 522#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 523#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 524#define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 525#define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 526#define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8)) 527#define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8)) 528#define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8)) 529#define SQLITE_IOERR_DATA (SQLITE_IOERR | (32<<8)) 530#define SQLITE_IOERR_CORRUPTFS (SQLITE_IOERR | (33<<8)) 531#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 532#define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8)) 533#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 534#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 535#define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8)) 536#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 537#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 538#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 539#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 540#define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */ 541#define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8)) 542#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 543#define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8)) 544#define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8)) 545#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 546#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 547#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 548#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 549#define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8)) 550#define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8)) 551#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 552#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 553#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 554#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 555#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 556#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 557#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 558#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 559#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 560#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 561#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 562#define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8)) 563#define SQLITE_CONSTRAINT_DATATYPE (SQLITE_CONSTRAINT |(12<<8)) 564#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 565#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 566#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 567#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 568#define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 569#define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) /* internal use only */ 570 571/* 572** CAPI3REF: Flags For File Open Operations 573** 574** These bit values are intended for use in the 575** 3rd parameter to the [sqlite3_open_v2()] interface and 576** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 577** 578** Only those flags marked as "Ok for sqlite3_open_v2()" may be 579** used as the third argument to the [sqlite3_open_v2()] interface. 580** The other flags have historically been ignored by sqlite3_open_v2(), 581** though future versions of SQLite might change so that an error is 582** raised if any of the disallowed bits are passed into sqlite3_open_v2(). 583** Applications should not depend on the historical behavior. 584** 585** Note in particular that passing the SQLITE_OPEN_EXCLUSIVE flag into 586** [sqlite3_open_v2()] does *not* cause the underlying database file 587** to be opened using O_EXCL. Passing SQLITE_OPEN_EXCLUSIVE into 588** [sqlite3_open_v2()] has historically be a no-op and might become an 589** error in future versions of SQLite. 590*/ 591#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 592#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 593#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 594#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 595#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 596#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 597#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 598#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 599#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 600#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 601#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 602#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 603#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 604#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 605#define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */ 606#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 607#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 608#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 609#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 610#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 611#define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */ 612#define SQLITE_OPEN_EXRESCODE 0x02000000 /* Extended result codes */ 613 614/* Reserved: 0x00F00000 */ 615/* Legacy compatibility: */ 616#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 617 618 619/* 620** CAPI3REF: Device Characteristics 621** 622** The xDeviceCharacteristics method of the [sqlite3_io_methods] 623** object returns an integer which is a vector of these 624** bit values expressing I/O characteristics of the mass storage 625** device that holds the file that the [sqlite3_io_methods] 626** refers to. 627** 628** The SQLITE_IOCAP_ATOMIC property means that all writes of 629** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 630** mean that writes of blocks that are nnn bytes in size and 631** are aligned to an address which is an integer multiple of 632** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 633** that when data is appended to a file, the data is appended 634** first then the size of the file is extended, never the other 635** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 636** information is written to disk in the same order as calls 637** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 638** after reboot following a crash or power loss, the only bytes in a 639** file that were written at the application level might have changed 640** and that adjacent bytes, even bytes within the same sector are 641** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 642** flag indicates that a file cannot be deleted when open. The 643** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 644** read-only media and cannot be changed even by processes with 645** elevated privileges. 646** 647** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 648** filesystem supports doing multiple write operations atomically when those 649** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 650** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 651*/ 652#define SQLITE_IOCAP_ATOMIC 0x00000001 653#define SQLITE_IOCAP_ATOMIC512 0x00000002 654#define SQLITE_IOCAP_ATOMIC1K 0x00000004 655#define SQLITE_IOCAP_ATOMIC2K 0x00000008 656#define SQLITE_IOCAP_ATOMIC4K 0x00000010 657#define SQLITE_IOCAP_ATOMIC8K 0x00000020 658#define SQLITE_IOCAP_ATOMIC16K 0x00000040 659#define SQLITE_IOCAP_ATOMIC32K 0x00000080 660#define SQLITE_IOCAP_ATOMIC64K 0x00000100 661#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 662#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 663#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 664#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 665#define SQLITE_IOCAP_IMMUTABLE 0x00002000 666#define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 667 668/* 669** CAPI3REF: File Locking Levels 670** 671** SQLite uses one of these integer values as the second 672** argument to calls it makes to the xLock() and xUnlock() methods 673** of an [sqlite3_io_methods] object. These values are ordered from 674** lest restrictive to most restrictive. 675** 676** The argument to xLock() is always SHARED or higher. The argument to 677** xUnlock is either SHARED or NONE. 678*/ 679#define SQLITE_LOCK_NONE 0 /* xUnlock() only */ 680#define SQLITE_LOCK_SHARED 1 /* xLock() or xUnlock() */ 681#define SQLITE_LOCK_RESERVED 2 /* xLock() only */ 682#define SQLITE_LOCK_PENDING 3 /* xLock() only */ 683#define SQLITE_LOCK_EXCLUSIVE 4 /* xLock() only */ 684 685/* 686** CAPI3REF: Synchronization Type Flags 687** 688** When SQLite invokes the xSync() method of an 689** [sqlite3_io_methods] object it uses a combination of 690** these integer values as the second argument. 691** 692** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 693** sync operation only needs to flush data to mass storage. Inode 694** information need not be flushed. If the lower four bits of the flag 695** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 696** If the lower four bits equal SQLITE_SYNC_FULL, that means 697** to use Mac OS X style fullsync instead of fsync(). 698** 699** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 700** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 701** settings. The [synchronous pragma] determines when calls to the 702** xSync VFS method occur and applies uniformly across all platforms. 703** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 704** energetic or rigorous or forceful the sync operations are and 705** only make a difference on Mac OSX for the default SQLite code. 706** (Third-party VFS implementations might also make the distinction 707** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 708** operating systems natively supported by SQLite, only Mac OSX 709** cares about the difference.) 710*/ 711#define SQLITE_SYNC_NORMAL 0x00002 712#define SQLITE_SYNC_FULL 0x00003 713#define SQLITE_SYNC_DATAONLY 0x00010 714 715/* 716** CAPI3REF: OS Interface Open File Handle 717** 718** An [sqlite3_file] object represents an open file in the 719** [sqlite3_vfs | OS interface layer]. Individual OS interface 720** implementations will 721** want to subclass this object by appending additional fields 722** for their own use. The pMethods entry is a pointer to an 723** [sqlite3_io_methods] object that defines methods for performing 724** I/O operations on the open file. 725*/ 726typedef struct sqlite3_file sqlite3_file; 727struct sqlite3_file { 728 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 729}; 730 731/* 732** CAPI3REF: OS Interface File Virtual Methods Object 733** 734** Every file opened by the [sqlite3_vfs.xOpen] method populates an 735** [sqlite3_file] object (or, more commonly, a subclass of the 736** [sqlite3_file] object) with a pointer to an instance of this object. 737** This object defines the methods used to perform various operations 738** against the open file represented by the [sqlite3_file] object. 739** 740** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 741** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 742** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 743** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 744** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 745** to NULL. 746** 747** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 748** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 749** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 750** flag may be ORed in to indicate that only the data of the file 751** and not its inode needs to be synced. 752** 753** The integer values to xLock() and xUnlock() are one of 754** <ul> 755** <li> [SQLITE_LOCK_NONE], 756** <li> [SQLITE_LOCK_SHARED], 757** <li> [SQLITE_LOCK_RESERVED], 758** <li> [SQLITE_LOCK_PENDING], or 759** <li> [SQLITE_LOCK_EXCLUSIVE]. 760** </ul> 761** xLock() upgrades the database file lock. In other words, xLock() moves the 762** database file lock in the direction NONE toward EXCLUSIVE. The argument to 763** xLock() is always on of SHARED, RESERVED, PENDING, or EXCLUSIVE, never 764** SQLITE_LOCK_NONE. If the database file lock is already at or above the 765** requested lock, then the call to xLock() is a no-op. 766** xUnlock() downgrades the database file lock to either SHARED or NONE. 767* If the lock is already at or below the requested lock state, then the call 768** to xUnlock() is a no-op. 769** The xCheckReservedLock() method checks whether any database connection, 770** either in this process or in some other process, is holding a RESERVED, 771** PENDING, or EXCLUSIVE lock on the file. It returns true 772** if such a lock exists and false otherwise. 773** 774** The xFileControl() method is a generic interface that allows custom 775** VFS implementations to directly control an open file using the 776** [sqlite3_file_control()] interface. The second "op" argument is an 777** integer opcode. The third argument is a generic pointer intended to 778** point to a structure that may contain arguments or space in which to 779** write return values. Potential uses for xFileControl() might be 780** functions to enable blocking locks with timeouts, to change the 781** locking strategy (for example to use dot-file locks), to inquire 782** about the status of a lock, or to break stale locks. The SQLite 783** core reserves all opcodes less than 100 for its own use. 784** A [file control opcodes | list of opcodes] less than 100 is available. 785** Applications that define a custom xFileControl method should use opcodes 786** greater than 100 to avoid conflicts. VFS implementations should 787** return [SQLITE_NOTFOUND] for file control opcodes that they do not 788** recognize. 789** 790** The xSectorSize() method returns the sector size of the 791** device that underlies the file. The sector size is the 792** minimum write that can be performed without disturbing 793** other bytes in the file. The xDeviceCharacteristics() 794** method returns a bit vector describing behaviors of the 795** underlying device: 796** 797** <ul> 798** <li> [SQLITE_IOCAP_ATOMIC] 799** <li> [SQLITE_IOCAP_ATOMIC512] 800** <li> [SQLITE_IOCAP_ATOMIC1K] 801** <li> [SQLITE_IOCAP_ATOMIC2K] 802** <li> [SQLITE_IOCAP_ATOMIC4K] 803** <li> [SQLITE_IOCAP_ATOMIC8K] 804** <li> [SQLITE_IOCAP_ATOMIC16K] 805** <li> [SQLITE_IOCAP_ATOMIC32K] 806** <li> [SQLITE_IOCAP_ATOMIC64K] 807** <li> [SQLITE_IOCAP_SAFE_APPEND] 808** <li> [SQLITE_IOCAP_SEQUENTIAL] 809** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 810** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 811** <li> [SQLITE_IOCAP_IMMUTABLE] 812** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 813** </ul> 814** 815** The SQLITE_IOCAP_ATOMIC property means that all writes of 816** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 817** mean that writes of blocks that are nnn bytes in size and 818** are aligned to an address which is an integer multiple of 819** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 820** that when data is appended to a file, the data is appended 821** first then the size of the file is extended, never the other 822** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 823** information is written to disk in the same order as calls 824** to xWrite(). 825** 826** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 827** in the unread portions of the buffer with zeros. A VFS that 828** fails to zero-fill short reads might seem to work. However, 829** failure to zero-fill short reads will eventually lead to 830** database corruption. 831*/ 832typedef struct sqlite3_io_methods sqlite3_io_methods; 833struct sqlite3_io_methods { 834 int iVersion; 835 int (*xClose)(sqlite3_file*); 836 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 837 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 838 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 839 int (*xSync)(sqlite3_file*, int flags); 840 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 841 int (*xLock)(sqlite3_file*, int); 842 int (*xUnlock)(sqlite3_file*, int); 843 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 844 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 845 int (*xSectorSize)(sqlite3_file*); 846 int (*xDeviceCharacteristics)(sqlite3_file*); 847 /* Methods above are valid for version 1 */ 848 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 849 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 850 void (*xShmBarrier)(sqlite3_file*); 851 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 852 /* Methods above are valid for version 2 */ 853 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 854 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 855 /* Methods above are valid for version 3 */ 856 /* Additional methods may be added in future releases */ 857}; 858 859/* 860** CAPI3REF: Standard File Control Opcodes 861** KEYWORDS: {file control opcodes} {file control opcode} 862** 863** These integer constants are opcodes for the xFileControl method 864** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 865** interface. 866** 867** <ul> 868** <li>[[SQLITE_FCNTL_LOCKSTATE]] 869** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 870** opcode causes the xFileControl method to write the current state of 871** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 872** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 873** into an integer that the pArg argument points to. 874** This capability is only available if SQLite is compiled with [SQLITE_DEBUG]. 875** 876** <li>[[SQLITE_FCNTL_SIZE_HINT]] 877** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 878** layer a hint of how large the database file will grow to be during the 879** current transaction. This hint is not guaranteed to be accurate but it 880** is often close. The underlying VFS might choose to preallocate database 881** file space based on this hint in order to help writes to the database 882** file run faster. 883** 884** <li>[[SQLITE_FCNTL_SIZE_LIMIT]] 885** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that 886** implements [sqlite3_deserialize()] to set an upper bound on the size 887** of the in-memory database. The argument is a pointer to a [sqlite3_int64]. 888** If the integer pointed to is negative, then it is filled in with the 889** current limit. Otherwise the limit is set to the larger of the value 890** of the integer pointed to and the current database size. The integer 891** pointed to is set to the new limit. 892** 893** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 894** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 895** extends and truncates the database file in chunks of a size specified 896** by the user. The fourth argument to [sqlite3_file_control()] should 897** point to an integer (type int) containing the new chunk-size to use 898** for the nominated database. Allocating database file space in large 899** chunks (say 1MB at a time), may reduce file-system fragmentation and 900** improve performance on some systems. 901** 902** <li>[[SQLITE_FCNTL_FILE_POINTER]] 903** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 904** to the [sqlite3_file] object associated with a particular database 905** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 906** 907** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 908** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 909** to the [sqlite3_file] object associated with the journal file (either 910** the [rollback journal] or the [write-ahead log]) for a particular database 911** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 912** 913** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 914** No longer in use. 915** 916** <li>[[SQLITE_FCNTL_SYNC]] 917** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 918** sent to the VFS immediately before the xSync method is invoked on a 919** database file descriptor. Or, if the xSync method is not invoked 920** because the user has configured SQLite with 921** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 922** of the xSync method. In most cases, the pointer argument passed with 923** this file-control is NULL. However, if the database file is being synced 924** as part of a multi-database commit, the argument points to a nul-terminated 925** string containing the transactions super-journal file name. VFSes that 926** do not need this signal should silently ignore this opcode. Applications 927** should not call [sqlite3_file_control()] with this opcode as doing so may 928** disrupt the operation of the specialized VFSes that do require it. 929** 930** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 931** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 932** and sent to the VFS after a transaction has been committed immediately 933** but before the database is unlocked. VFSes that do not need this signal 934** should silently ignore this opcode. Applications should not call 935** [sqlite3_file_control()] with this opcode as doing so may disrupt the 936** operation of the specialized VFSes that do require it. 937** 938** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 939** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 940** retry counts and intervals for certain disk I/O operations for the 941** windows [VFS] in order to provide robustness in the presence of 942** anti-virus programs. By default, the windows VFS will retry file read, 943** file write, and file delete operations up to 10 times, with a delay 944** of 25 milliseconds before the first retry and with the delay increasing 945** by an additional 25 milliseconds with each subsequent retry. This 946** opcode allows these two values (10 retries and 25 milliseconds of delay) 947** to be adjusted. The values are changed for all database connections 948** within the same process. The argument is a pointer to an array of two 949** integers where the first integer is the new retry count and the second 950** integer is the delay. If either integer is negative, then the setting 951** is not changed but instead the prior value of that setting is written 952** into the array entry, allowing the current retry settings to be 953** interrogated. The zDbName parameter is ignored. 954** 955** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 956** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 957** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 958** write ahead log ([WAL file]) and shared memory 959** files used for transaction control 960** are automatically deleted when the latest connection to the database 961** closes. Setting persistent WAL mode causes those files to persist after 962** close. Persisting the files is useful when other processes that do not 963** have write permission on the directory containing the database file want 964** to read the database file, as the WAL and shared memory files must exist 965** in order for the database to be readable. The fourth parameter to 966** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 967** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 968** WAL mode. If the integer is -1, then it is overwritten with the current 969** WAL persistence setting. 970** 971** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 972** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 973** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 974** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 975** xDeviceCharacteristics methods. The fourth parameter to 976** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 977** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 978** mode. If the integer is -1, then it is overwritten with the current 979** zero-damage mode setting. 980** 981** <li>[[SQLITE_FCNTL_OVERWRITE]] 982** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 983** a write transaction to indicate that, unless it is rolled back for some 984** reason, the entire database file will be overwritten by the current 985** transaction. This is used by VACUUM operations. 986** 987** <li>[[SQLITE_FCNTL_VFSNAME]] 988** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 989** all [VFSes] in the VFS stack. The names are of all VFS shims and the 990** final bottom-level VFS are written into memory obtained from 991** [sqlite3_malloc()] and the result is stored in the char* variable 992** that the fourth parameter of [sqlite3_file_control()] points to. 993** The caller is responsible for freeing the memory when done. As with 994** all file-control actions, there is no guarantee that this will actually 995** do anything. Callers should initialize the char* variable to a NULL 996** pointer in case this file-control is not implemented. This file-control 997** is intended for diagnostic use only. 998** 999** <li>[[SQLITE_FCNTL_VFS_POINTER]] 1000** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 1001** [VFSes] currently in use. ^(The argument X in 1002** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 1003** of type "[sqlite3_vfs] **". This opcodes will set *X 1004** to a pointer to the top-level VFS.)^ 1005** ^When there are multiple VFS shims in the stack, this opcode finds the 1006** upper-most shim only. 1007** 1008** <li>[[SQLITE_FCNTL_PRAGMA]] 1009** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 1010** file control is sent to the open [sqlite3_file] object corresponding 1011** to the database file to which the pragma statement refers. ^The argument 1012** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 1013** pointers to strings (char**) in which the second element of the array 1014** is the name of the pragma and the third element is the argument to the 1015** pragma or NULL if the pragma has no argument. ^The handler for an 1016** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 1017** of the char** argument point to a string obtained from [sqlite3_mprintf()] 1018** or the equivalent and that string will become the result of the pragma or 1019** the error message if the pragma fails. ^If the 1020** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 1021** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 1022** file control returns [SQLITE_OK], then the parser assumes that the 1023** VFS has handled the PRAGMA itself and the parser generates a no-op 1024** prepared statement if result string is NULL, or that returns a copy 1025** of the result string if the string is non-NULL. 1026** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 1027** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 1028** that the VFS encountered an error while handling the [PRAGMA] and the 1029** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 1030** file control occurs at the beginning of pragma statement analysis and so 1031** it is able to override built-in [PRAGMA] statements. 1032** 1033** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 1034** ^The [SQLITE_FCNTL_BUSYHANDLER] 1035** file-control may be invoked by SQLite on the database file handle 1036** shortly after it is opened in order to provide a custom VFS with access 1037** to the connection's busy-handler callback. The argument is of type (void**) 1038** - an array of two (void *) values. The first (void *) actually points 1039** to a function of type (int (*)(void *)). In order to invoke the connection's 1040** busy-handler, this function should be invoked with the second (void *) in 1041** the array as the only argument. If it returns non-zero, then the operation 1042** should be retried. If it returns zero, the custom VFS should abandon the 1043** current operation. 1044** 1045** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 1046** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 1047** to have SQLite generate a 1048** temporary filename using the same algorithm that is followed to generate 1049** temporary filenames for TEMP tables and other internal uses. The 1050** argument should be a char** which will be filled with the filename 1051** written into memory obtained from [sqlite3_malloc()]. The caller should 1052** invoke [sqlite3_free()] on the result to avoid a memory leak. 1053** 1054** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 1055** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 1056** maximum number of bytes that will be used for memory-mapped I/O. 1057** The argument is a pointer to a value of type sqlite3_int64 that 1058** is an advisory maximum number of bytes in the file to memory map. The 1059** pointer is overwritten with the old value. The limit is not changed if 1060** the value originally pointed to is negative, and so the current limit 1061** can be queried by passing in a pointer to a negative number. This 1062** file-control is used internally to implement [PRAGMA mmap_size]. 1063** 1064** <li>[[SQLITE_FCNTL_TRACE]] 1065** The [SQLITE_FCNTL_TRACE] file control provides advisory information 1066** to the VFS about what the higher layers of the SQLite stack are doing. 1067** This file control is used by some VFS activity tracing [shims]. 1068** The argument is a zero-terminated string. Higher layers in the 1069** SQLite stack may generate instances of this file control if 1070** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 1071** 1072** <li>[[SQLITE_FCNTL_HAS_MOVED]] 1073** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 1074** pointer to an integer and it writes a boolean into that integer depending 1075** on whether or not the file has been renamed, moved, or deleted since it 1076** was first opened. 1077** 1078** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 1079** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1080** underlying native file handle associated with a file handle. This file 1081** control interprets its argument as a pointer to a native file handle and 1082** writes the resulting value there. 1083** 1084** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1085** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1086** opcode causes the xFileControl method to swap the file handle with the one 1087** pointed to by the pArg argument. This capability is used during testing 1088** and only needs to be supported when SQLITE_TEST is defined. 1089** 1090** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1091** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1092** be advantageous to block on the next WAL lock if the lock is not immediately 1093** available. The WAL subsystem issues this signal during rare 1094** circumstances in order to fix a problem with priority inversion. 1095** Applications should <em>not</em> use this file-control. 1096** 1097** <li>[[SQLITE_FCNTL_ZIPVFS]] 1098** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1099** VFS should return SQLITE_NOTFOUND for this opcode. 1100** 1101** <li>[[SQLITE_FCNTL_RBU]] 1102** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1103** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1104** this opcode. 1105** 1106** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1107** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1108** the file descriptor is placed in "batch write mode", which 1109** means all subsequent write operations will be deferred and done 1110** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1111** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1112** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1113** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1114** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1115** no VFS interface calls on the same [sqlite3_file] file descriptor 1116** except for calls to the xWrite method and the xFileControl method 1117** with [SQLITE_FCNTL_SIZE_HINT]. 1118** 1119** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1120** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1121** operations since the previous successful call to 1122** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1123** This file control returns [SQLITE_OK] if and only if the writes were 1124** all performed successfully and have been committed to persistent storage. 1125** ^Regardless of whether or not it is successful, this file control takes 1126** the file descriptor out of batch write mode so that all subsequent 1127** write operations are independent. 1128** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1129** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1130** 1131** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1132** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1133** operations since the previous successful call to 1134** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1135** ^This file control takes the file descriptor out of batch write mode 1136** so that all subsequent write operations are independent. 1137** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1138** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1139** 1140** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]] 1141** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS 1142** to block for up to M milliseconds before failing when attempting to 1143** obtain a file lock using the xLock or xShmLock methods of the VFS. 1144** The parameter is a pointer to a 32-bit signed integer that contains 1145** the value that M is to be set to. Before returning, the 32-bit signed 1146** integer is overwritten with the previous value of M. 1147** 1148** <li>[[SQLITE_FCNTL_DATA_VERSION]] 1149** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to 1150** a database file. The argument is a pointer to a 32-bit unsigned integer. 1151** The "data version" for the pager is written into the pointer. The 1152** "data version" changes whenever any change occurs to the corresponding 1153** database file, either through SQL statements on the same database 1154** connection or through transactions committed by separate database 1155** connections possibly in other processes. The [sqlite3_total_changes()] 1156** interface can be used to find if any database on the connection has changed, 1157** but that interface responds to changes on TEMP as well as MAIN and does 1158** not provide a mechanism to detect changes to MAIN only. Also, the 1159** [sqlite3_total_changes()] interface responds to internal changes only and 1160** omits changes made by other database connections. The 1161** [PRAGMA data_version] command provides a mechanism to detect changes to 1162** a single attached database that occur due to other database connections, 1163** but omits changes implemented by the database connection on which it is 1164** called. This file control is the only mechanism to detect changes that 1165** happen either internally or externally and that are associated with 1166** a particular attached database. 1167** 1168** <li>[[SQLITE_FCNTL_CKPT_START]] 1169** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint 1170** in wal mode before the client starts to copy pages from the wal 1171** file to the database file. 1172** 1173** <li>[[SQLITE_FCNTL_CKPT_DONE]] 1174** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint 1175** in wal mode after the client has finished copying pages from the wal 1176** file to the database file, but before the *-shm file is updated to 1177** record the fact that the pages have been checkpointed. 1178** </ul> 1179** 1180** <li>[[SQLITE_FCNTL_EXTERNAL_READER]] 1181** The EXPERIMENTAL [SQLITE_FCNTL_EXTERNAL_READER] opcode is used to detect 1182** whether or not there is a database client in another process with a wal-mode 1183** transaction open on the database or not. It is only available on unix.The 1184** (void*) argument passed with this file-control should be a pointer to a 1185** value of type (int). The integer value is set to 1 if the database is a wal 1186** mode database and there exists at least one client in another process that 1187** currently has an SQL transaction open on the database. It is set to 0 if 1188** the database is not a wal-mode db, or if there is no such connection in any 1189** other process. This opcode cannot be used to detect transactions opened 1190** by clients within the current process, only within other processes. 1191** </ul> 1192** 1193** <li>[[SQLITE_FCNTL_CKSM_FILE]] 1194** Used by the cksmvfs VFS module only. 1195** 1196** <li>[[SQLITE_FCNTL_RESET_CACHE]] 1197** If there is currently no transaction open on the database, and the 1198** database is not a temp db, then this file-control purges the contents 1199** of the in-memory page cache. If there is an open transaction, or if 1200** the db is a temp-db, it is a no-op, not an error. 1201** </ul> 1202*/ 1203#define SQLITE_FCNTL_LOCKSTATE 1 1204#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1205#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1206#define SQLITE_FCNTL_LAST_ERRNO 4 1207#define SQLITE_FCNTL_SIZE_HINT 5 1208#define SQLITE_FCNTL_CHUNK_SIZE 6 1209#define SQLITE_FCNTL_FILE_POINTER 7 1210#define SQLITE_FCNTL_SYNC_OMITTED 8 1211#define SQLITE_FCNTL_WIN32_AV_RETRY 9 1212#define SQLITE_FCNTL_PERSIST_WAL 10 1213#define SQLITE_FCNTL_OVERWRITE 11 1214#define SQLITE_FCNTL_VFSNAME 12 1215#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1216#define SQLITE_FCNTL_PRAGMA 14 1217#define SQLITE_FCNTL_BUSYHANDLER 15 1218#define SQLITE_FCNTL_TEMPFILENAME 16 1219#define SQLITE_FCNTL_MMAP_SIZE 18 1220#define SQLITE_FCNTL_TRACE 19 1221#define SQLITE_FCNTL_HAS_MOVED 20 1222#define SQLITE_FCNTL_SYNC 21 1223#define SQLITE_FCNTL_COMMIT_PHASETWO 22 1224#define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1225#define SQLITE_FCNTL_WAL_BLOCK 24 1226#define SQLITE_FCNTL_ZIPVFS 25 1227#define SQLITE_FCNTL_RBU 26 1228#define SQLITE_FCNTL_VFS_POINTER 27 1229#define SQLITE_FCNTL_JOURNAL_POINTER 28 1230#define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1231#define SQLITE_FCNTL_PDB 30 1232#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1233#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1234#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1235#define SQLITE_FCNTL_LOCK_TIMEOUT 34 1236#define SQLITE_FCNTL_DATA_VERSION 35 1237#define SQLITE_FCNTL_SIZE_LIMIT 36 1238#define SQLITE_FCNTL_CKPT_DONE 37 1239#define SQLITE_FCNTL_RESERVE_BYTES 38 1240#define SQLITE_FCNTL_CKPT_START 39 1241#define SQLITE_FCNTL_EXTERNAL_READER 40 1242#define SQLITE_FCNTL_CKSM_FILE 41 1243#define SQLITE_FCNTL_RESET_CACHE 42 1244 1245/* deprecated names */ 1246#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1247#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1248#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1249 1250 1251/* 1252** CAPI3REF: Mutex Handle 1253** 1254** The mutex module within SQLite defines [sqlite3_mutex] to be an 1255** abstract type for a mutex object. The SQLite core never looks 1256** at the internal representation of an [sqlite3_mutex]. It only 1257** deals with pointers to the [sqlite3_mutex] object. 1258** 1259** Mutexes are created using [sqlite3_mutex_alloc()]. 1260*/ 1261typedef struct sqlite3_mutex sqlite3_mutex; 1262 1263/* 1264** CAPI3REF: Loadable Extension Thunk 1265** 1266** A pointer to the opaque sqlite3_api_routines structure is passed as 1267** the third parameter to entry points of [loadable extensions]. This 1268** structure must be typedefed in order to work around compiler warnings 1269** on some platforms. 1270*/ 1271typedef struct sqlite3_api_routines sqlite3_api_routines; 1272 1273/* 1274** CAPI3REF: File Name 1275** 1276** Type [sqlite3_filename] is used by SQLite to pass filenames to the 1277** xOpen method of a [VFS]. It may be cast to (const char*) and treated 1278** as a normal, nul-terminated, UTF-8 buffer containing the filename, but 1279** may also be passed to special APIs such as: 1280** 1281** <ul> 1282** <li> sqlite3_filename_database() 1283** <li> sqlite3_filename_journal() 1284** <li> sqlite3_filename_wal() 1285** <li> sqlite3_uri_parameter() 1286** <li> sqlite3_uri_boolean() 1287** <li> sqlite3_uri_int64() 1288** <li> sqlite3_uri_key() 1289** </ul> 1290*/ 1291typedef const char *sqlite3_filename; 1292 1293/* 1294** CAPI3REF: OS Interface Object 1295** 1296** An instance of the sqlite3_vfs object defines the interface between 1297** the SQLite core and the underlying operating system. The "vfs" 1298** in the name of the object stands for "virtual file system". See 1299** the [VFS | VFS documentation] for further information. 1300** 1301** The VFS interface is sometimes extended by adding new methods onto 1302** the end. Each time such an extension occurs, the iVersion field 1303** is incremented. The iVersion value started out as 1 in 1304** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 1305** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased 1306** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields 1307** may be appended to the sqlite3_vfs object and the iVersion value 1308** may increase again in future versions of SQLite. 1309** Note that due to an oversight, the structure 1310** of the sqlite3_vfs object changed in the transition from 1311** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] 1312** and yet the iVersion field was not increased. 1313** 1314** The szOsFile field is the size of the subclassed [sqlite3_file] 1315** structure used by this VFS. mxPathname is the maximum length of 1316** a pathname in this VFS. 1317** 1318** Registered sqlite3_vfs objects are kept on a linked list formed by 1319** the pNext pointer. The [sqlite3_vfs_register()] 1320** and [sqlite3_vfs_unregister()] interfaces manage this list 1321** in a thread-safe way. The [sqlite3_vfs_find()] interface 1322** searches the list. Neither the application code nor the VFS 1323** implementation should use the pNext pointer. 1324** 1325** The pNext field is the only field in the sqlite3_vfs 1326** structure that SQLite will ever modify. SQLite will only access 1327** or modify this field while holding a particular static mutex. 1328** The application should never modify anything within the sqlite3_vfs 1329** object once the object has been registered. 1330** 1331** The zName field holds the name of the VFS module. The name must 1332** be unique across all VFS modules. 1333** 1334** [[sqlite3_vfs.xOpen]] 1335** ^SQLite guarantees that the zFilename parameter to xOpen 1336** is either a NULL pointer or string obtained 1337** from xFullPathname() with an optional suffix added. 1338** ^If a suffix is added to the zFilename parameter, it will 1339** consist of a single "-" character followed by no more than 1340** 11 alphanumeric and/or "-" characters. 1341** ^SQLite further guarantees that 1342** the string will be valid and unchanged until xClose() is 1343** called. Because of the previous sentence, 1344** the [sqlite3_file] can safely store a pointer to the 1345** filename if it needs to remember the filename for some reason. 1346** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1347** must invent its own temporary name for the file. ^Whenever the 1348** xFilename parameter is NULL it will also be the case that the 1349** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1350** 1351** The flags argument to xOpen() includes all bits set in 1352** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1353** or [sqlite3_open16()] is used, then flags includes at least 1354** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1355** If xOpen() opens a file read-only then it sets *pOutFlags to 1356** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1357** 1358** ^(SQLite will also add one of the following flags to the xOpen() 1359** call, depending on the object being opened: 1360** 1361** <ul> 1362** <li> [SQLITE_OPEN_MAIN_DB] 1363** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1364** <li> [SQLITE_OPEN_TEMP_DB] 1365** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1366** <li> [SQLITE_OPEN_TRANSIENT_DB] 1367** <li> [SQLITE_OPEN_SUBJOURNAL] 1368** <li> [SQLITE_OPEN_SUPER_JOURNAL] 1369** <li> [SQLITE_OPEN_WAL] 1370** </ul>)^ 1371** 1372** The file I/O implementation can use the object type flags to 1373** change the way it deals with files. For example, an application 1374** that does not care about crash recovery or rollback might make 1375** the open of a journal file a no-op. Writes to this journal would 1376** also be no-ops, and any attempt to read the journal would return 1377** SQLITE_IOERR. Or the implementation might recognize that a database 1378** file will be doing page-aligned sector reads and writes in a random 1379** order and set up its I/O subsystem accordingly. 1380** 1381** SQLite might also add one of the following flags to the xOpen method: 1382** 1383** <ul> 1384** <li> [SQLITE_OPEN_DELETEONCLOSE] 1385** <li> [SQLITE_OPEN_EXCLUSIVE] 1386** </ul> 1387** 1388** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1389** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1390** will be set for TEMP databases and their journals, transient 1391** databases, and subjournals. 1392** 1393** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1394** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1395** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1396** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1397** SQLITE_OPEN_CREATE, is used to indicate that file should always 1398** be created, and that it is an error if it already exists. 1399** It is <i>not</i> used to indicate the file should be opened 1400** for exclusive access. 1401** 1402** ^At least szOsFile bytes of memory are allocated by SQLite 1403** to hold the [sqlite3_file] structure passed as the third 1404** argument to xOpen. The xOpen method does not have to 1405** allocate the structure; it should just fill it in. Note that 1406** the xOpen method must set the sqlite3_file.pMethods to either 1407** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1408** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1409** element will be valid after xOpen returns regardless of the success 1410** or failure of the xOpen call. 1411** 1412** [[sqlite3_vfs.xAccess]] 1413** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1414** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1415** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1416** to test whether a file is at least readable. The SQLITE_ACCESS_READ 1417** flag is never actually used and is not implemented in the built-in 1418** VFSes of SQLite. The file is named by the second argument and can be a 1419** directory. The xAccess method returns [SQLITE_OK] on success or some 1420** non-zero error code if there is an I/O error or if the name of 1421** the file given in the second argument is illegal. If SQLITE_OK 1422** is returned, then non-zero or zero is written into *pResOut to indicate 1423** whether or not the file is accessible. 1424** 1425** ^SQLite will always allocate at least mxPathname+1 bytes for the 1426** output buffer xFullPathname. The exact size of the output buffer 1427** is also passed as a parameter to both methods. If the output buffer 1428** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1429** handled as a fatal error by SQLite, vfs implementations should endeavor 1430** to prevent this by setting mxPathname to a sufficiently large value. 1431** 1432** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1433** interfaces are not strictly a part of the filesystem, but they are 1434** included in the VFS structure for completeness. 1435** The xRandomness() function attempts to return nBytes bytes 1436** of good-quality randomness into zOut. The return value is 1437** the actual number of bytes of randomness obtained. 1438** The xSleep() method causes the calling thread to sleep for at 1439** least the number of microseconds given. ^The xCurrentTime() 1440** method returns a Julian Day Number for the current date and time as 1441** a floating point value. 1442** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1443** Day Number multiplied by 86400000 (the number of milliseconds in 1444** a 24-hour day). 1445** ^SQLite will use the xCurrentTimeInt64() method to get the current 1446** date and time if that method is available (if iVersion is 2 or 1447** greater and the function pointer is not NULL) and will fall back 1448** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1449** 1450** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1451** are not used by the SQLite core. These optional interfaces are provided 1452** by some VFSes to facilitate testing of the VFS code. By overriding 1453** system calls with functions under its control, a test program can 1454** simulate faults and error conditions that would otherwise be difficult 1455** or impossible to induce. The set of system calls that can be overridden 1456** varies from one VFS to another, and from one version of the same VFS to the 1457** next. Applications that use these interfaces must be prepared for any 1458** or all of these interfaces to be NULL or for their behavior to change 1459** from one release to the next. Applications must not attempt to access 1460** any of these methods if the iVersion of the VFS is less than 3. 1461*/ 1462typedef struct sqlite3_vfs sqlite3_vfs; 1463typedef void (*sqlite3_syscall_ptr)(void); 1464struct sqlite3_vfs { 1465 int iVersion; /* Structure version number (currently 3) */ 1466 int szOsFile; /* Size of subclassed sqlite3_file */ 1467 int mxPathname; /* Maximum file pathname length */ 1468 sqlite3_vfs *pNext; /* Next registered VFS */ 1469 const char *zName; /* Name of this virtual file system */ 1470 void *pAppData; /* Pointer to application-specific data */ 1471 int (*xOpen)(sqlite3_vfs*, sqlite3_filename zName, sqlite3_file*, 1472 int flags, int *pOutFlags); 1473 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1474 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1475 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1476 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1477 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1478 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1479 void (*xDlClose)(sqlite3_vfs*, void*); 1480 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1481 int (*xSleep)(sqlite3_vfs*, int microseconds); 1482 int (*xCurrentTime)(sqlite3_vfs*, double*); 1483 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1484 /* 1485 ** The methods above are in version 1 of the sqlite_vfs object 1486 ** definition. Those that follow are added in version 2 or later 1487 */ 1488 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1489 /* 1490 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1491 ** Those below are for version 3 and greater. 1492 */ 1493 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1494 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1495 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1496 /* 1497 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1498 ** New fields may be appended in future versions. The iVersion 1499 ** value will increment whenever this happens. 1500 */ 1501}; 1502 1503/* 1504** CAPI3REF: Flags for the xAccess VFS method 1505** 1506** These integer constants can be used as the third parameter to 1507** the xAccess method of an [sqlite3_vfs] object. They determine 1508** what kind of permissions the xAccess method is looking for. 1509** With SQLITE_ACCESS_EXISTS, the xAccess method 1510** simply checks whether the file exists. 1511** With SQLITE_ACCESS_READWRITE, the xAccess method 1512** checks whether the named directory is both readable and writable 1513** (in other words, if files can be added, removed, and renamed within 1514** the directory). 1515** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1516** [temp_store_directory pragma], though this could change in a future 1517** release of SQLite. 1518** With SQLITE_ACCESS_READ, the xAccess method 1519** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1520** currently unused, though it might be used in a future release of 1521** SQLite. 1522*/ 1523#define SQLITE_ACCESS_EXISTS 0 1524#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1525#define SQLITE_ACCESS_READ 2 /* Unused */ 1526 1527/* 1528** CAPI3REF: Flags for the xShmLock VFS method 1529** 1530** These integer constants define the various locking operations 1531** allowed by the xShmLock method of [sqlite3_io_methods]. The 1532** following are the only legal combinations of flags to the 1533** xShmLock method: 1534** 1535** <ul> 1536** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1537** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1538** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1539** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1540** </ul> 1541** 1542** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1543** was given on the corresponding lock. 1544** 1545** The xShmLock method can transition between unlocked and SHARED or 1546** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1547** and EXCLUSIVE. 1548*/ 1549#define SQLITE_SHM_UNLOCK 1 1550#define SQLITE_SHM_LOCK 2 1551#define SQLITE_SHM_SHARED 4 1552#define SQLITE_SHM_EXCLUSIVE 8 1553 1554/* 1555** CAPI3REF: Maximum xShmLock index 1556** 1557** The xShmLock method on [sqlite3_io_methods] may use values 1558** between 0 and this upper bound as its "offset" argument. 1559** The SQLite core will never attempt to acquire or release a 1560** lock outside of this range 1561*/ 1562#define SQLITE_SHM_NLOCK 8 1563 1564 1565/* 1566** CAPI3REF: Initialize The SQLite Library 1567** 1568** ^The sqlite3_initialize() routine initializes the 1569** SQLite library. ^The sqlite3_shutdown() routine 1570** deallocates any resources that were allocated by sqlite3_initialize(). 1571** These routines are designed to aid in process initialization and 1572** shutdown on embedded systems. Workstation applications using 1573** SQLite normally do not need to invoke either of these routines. 1574** 1575** A call to sqlite3_initialize() is an "effective" call if it is 1576** the first time sqlite3_initialize() is invoked during the lifetime of 1577** the process, or if it is the first time sqlite3_initialize() is invoked 1578** following a call to sqlite3_shutdown(). ^(Only an effective call 1579** of sqlite3_initialize() does any initialization. All other calls 1580** are harmless no-ops.)^ 1581** 1582** A call to sqlite3_shutdown() is an "effective" call if it is the first 1583** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1584** an effective call to sqlite3_shutdown() does any deinitialization. 1585** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1586** 1587** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1588** is not. The sqlite3_shutdown() interface must only be called from a 1589** single thread. All open [database connections] must be closed and all 1590** other SQLite resources must be deallocated prior to invoking 1591** sqlite3_shutdown(). 1592** 1593** Among other things, ^sqlite3_initialize() will invoke 1594** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1595** will invoke sqlite3_os_end(). 1596** 1597** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1598** ^If for some reason, sqlite3_initialize() is unable to initialize 1599** the library (perhaps it is unable to allocate a needed resource such 1600** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1601** 1602** ^The sqlite3_initialize() routine is called internally by many other 1603** SQLite interfaces so that an application usually does not need to 1604** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1605** calls sqlite3_initialize() so the SQLite library will be automatically 1606** initialized when [sqlite3_open()] is called if it has not be initialized 1607** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1608** compile-time option, then the automatic calls to sqlite3_initialize() 1609** are omitted and the application must call sqlite3_initialize() directly 1610** prior to using any other SQLite interface. For maximum portability, 1611** it is recommended that applications always invoke sqlite3_initialize() 1612** directly prior to using any other SQLite interface. Future releases 1613** of SQLite may require this. In other words, the behavior exhibited 1614** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1615** default behavior in some future release of SQLite. 1616** 1617** The sqlite3_os_init() routine does operating-system specific 1618** initialization of the SQLite library. The sqlite3_os_end() 1619** routine undoes the effect of sqlite3_os_init(). Typical tasks 1620** performed by these routines include allocation or deallocation 1621** of static resources, initialization of global variables, 1622** setting up a default [sqlite3_vfs] module, or setting up 1623** a default configuration using [sqlite3_config()]. 1624** 1625** The application should never invoke either sqlite3_os_init() 1626** or sqlite3_os_end() directly. The application should only invoke 1627** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1628** interface is called automatically by sqlite3_initialize() and 1629** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1630** implementations for sqlite3_os_init() and sqlite3_os_end() 1631** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1632** When [custom builds | built for other platforms] 1633** (using the [SQLITE_OS_OTHER=1] compile-time 1634** option) the application must supply a suitable implementation for 1635** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1636** implementation of sqlite3_os_init() or sqlite3_os_end() 1637** must return [SQLITE_OK] on success and some other [error code] upon 1638** failure. 1639*/ 1640SQLITE_API int sqlite3_initialize(void); 1641SQLITE_API int sqlite3_shutdown(void); 1642SQLITE_API int sqlite3_os_init(void); 1643SQLITE_API int sqlite3_os_end(void); 1644 1645/* 1646** CAPI3REF: Configuring The SQLite Library 1647** 1648** The sqlite3_config() interface is used to make global configuration 1649** changes to SQLite in order to tune SQLite to the specific needs of 1650** the application. The default configuration is recommended for most 1651** applications and so this routine is usually not necessary. It is 1652** provided to support rare applications with unusual needs. 1653** 1654** <b>The sqlite3_config() interface is not threadsafe. The application 1655** must ensure that no other SQLite interfaces are invoked by other 1656** threads while sqlite3_config() is running.</b> 1657** 1658** The sqlite3_config() interface 1659** may only be invoked prior to library initialization using 1660** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1661** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1662** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1663** Note, however, that ^sqlite3_config() can be called as part of the 1664** implementation of an application-defined [sqlite3_os_init()]. 1665** 1666** The first argument to sqlite3_config() is an integer 1667** [configuration option] that determines 1668** what property of SQLite is to be configured. Subsequent arguments 1669** vary depending on the [configuration option] 1670** in the first argument. 1671** 1672** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1673** ^If the option is unknown or SQLite is unable to set the option 1674** then this routine returns a non-zero [error code]. 1675*/ 1676SQLITE_API int sqlite3_config(int, ...); 1677 1678/* 1679** CAPI3REF: Configure database connections 1680** METHOD: sqlite3 1681** 1682** The sqlite3_db_config() interface is used to make configuration 1683** changes to a [database connection]. The interface is similar to 1684** [sqlite3_config()] except that the changes apply to a single 1685** [database connection] (specified in the first argument). 1686** 1687** The second argument to sqlite3_db_config(D,V,...) is the 1688** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1689** that indicates what aspect of the [database connection] is being configured. 1690** Subsequent arguments vary depending on the configuration verb. 1691** 1692** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1693** the call is considered successful. 1694*/ 1695SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1696 1697/* 1698** CAPI3REF: Memory Allocation Routines 1699** 1700** An instance of this object defines the interface between SQLite 1701** and low-level memory allocation routines. 1702** 1703** This object is used in only one place in the SQLite interface. 1704** A pointer to an instance of this object is the argument to 1705** [sqlite3_config()] when the configuration option is 1706** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1707** By creating an instance of this object 1708** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1709** during configuration, an application can specify an alternative 1710** memory allocation subsystem for SQLite to use for all of its 1711** dynamic memory needs. 1712** 1713** Note that SQLite comes with several [built-in memory allocators] 1714** that are perfectly adequate for the overwhelming majority of applications 1715** and that this object is only useful to a tiny minority of applications 1716** with specialized memory allocation requirements. This object is 1717** also used during testing of SQLite in order to specify an alternative 1718** memory allocator that simulates memory out-of-memory conditions in 1719** order to verify that SQLite recovers gracefully from such 1720** conditions. 1721** 1722** The xMalloc, xRealloc, and xFree methods must work like the 1723** malloc(), realloc() and free() functions from the standard C library. 1724** ^SQLite guarantees that the second argument to 1725** xRealloc is always a value returned by a prior call to xRoundup. 1726** 1727** xSize should return the allocated size of a memory allocation 1728** previously obtained from xMalloc or xRealloc. The allocated size 1729** is always at least as big as the requested size but may be larger. 1730** 1731** The xRoundup method returns what would be the allocated size of 1732** a memory allocation given a particular requested size. Most memory 1733** allocators round up memory allocations at least to the next multiple 1734** of 8. Some allocators round up to a larger multiple or to a power of 2. 1735** Every memory allocation request coming in through [sqlite3_malloc()] 1736** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1737** that causes the corresponding memory allocation to fail. 1738** 1739** The xInit method initializes the memory allocator. For example, 1740** it might allocate any required mutexes or initialize internal data 1741** structures. The xShutdown method is invoked (indirectly) by 1742** [sqlite3_shutdown()] and should deallocate any resources acquired 1743** by xInit. The pAppData pointer is used as the only parameter to 1744** xInit and xShutdown. 1745** 1746** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes 1747** the xInit method, so the xInit method need not be threadsafe. The 1748** xShutdown method is only called from [sqlite3_shutdown()] so it does 1749** not need to be threadsafe either. For all other methods, SQLite 1750** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1751** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1752** it is by default) and so the methods are automatically serialized. 1753** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1754** methods must be threadsafe or else make their own arrangements for 1755** serialization. 1756** 1757** SQLite will never invoke xInit() more than once without an intervening 1758** call to xShutdown(). 1759*/ 1760typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1761struct sqlite3_mem_methods { 1762 void *(*xMalloc)(int); /* Memory allocation function */ 1763 void (*xFree)(void*); /* Free a prior allocation */ 1764 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1765 int (*xSize)(void*); /* Return the size of an allocation */ 1766 int (*xRoundup)(int); /* Round up request size to allocation size */ 1767 int (*xInit)(void*); /* Initialize the memory allocator */ 1768 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1769 void *pAppData; /* Argument to xInit() and xShutdown() */ 1770}; 1771 1772/* 1773** CAPI3REF: Configuration Options 1774** KEYWORDS: {configuration option} 1775** 1776** These constants are the available integer configuration options that 1777** can be passed as the first argument to the [sqlite3_config()] interface. 1778** 1779** New configuration options may be added in future releases of SQLite. 1780** Existing configuration options might be discontinued. Applications 1781** should check the return code from [sqlite3_config()] to make sure that 1782** the call worked. The [sqlite3_config()] interface will return a 1783** non-zero [error code] if a discontinued or unsupported configuration option 1784** is invoked. 1785** 1786** <dl> 1787** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1788** <dd>There are no arguments to this option. ^This option sets the 1789** [threading mode] to Single-thread. In other words, it disables 1790** all mutexing and puts SQLite into a mode where it can only be used 1791** by a single thread. ^If SQLite is compiled with 1792** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1793** it is not possible to change the [threading mode] from its default 1794** value of Single-thread and so [sqlite3_config()] will return 1795** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1796** configuration option.</dd> 1797** 1798** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1799** <dd>There are no arguments to this option. ^This option sets the 1800** [threading mode] to Multi-thread. In other words, it disables 1801** mutexing on [database connection] and [prepared statement] objects. 1802** The application is responsible for serializing access to 1803** [database connections] and [prepared statements]. But other mutexes 1804** are enabled so that SQLite will be safe to use in a multi-threaded 1805** environment as long as no two threads attempt to use the same 1806** [database connection] at the same time. ^If SQLite is compiled with 1807** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1808** it is not possible to set the Multi-thread [threading mode] and 1809** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1810** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1811** 1812** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1813** <dd>There are no arguments to this option. ^This option sets the 1814** [threading mode] to Serialized. In other words, this option enables 1815** all mutexes including the recursive 1816** mutexes on [database connection] and [prepared statement] objects. 1817** In this mode (which is the default when SQLite is compiled with 1818** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1819** to [database connections] and [prepared statements] so that the 1820** application is free to use the same [database connection] or the 1821** same [prepared statement] in different threads at the same time. 1822** ^If SQLite is compiled with 1823** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1824** it is not possible to set the Serialized [threading mode] and 1825** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1826** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1827** 1828** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1829** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1830** a pointer to an instance of the [sqlite3_mem_methods] structure. 1831** The argument specifies 1832** alternative low-level memory allocation routines to be used in place of 1833** the memory allocation routines built into SQLite.)^ ^SQLite makes 1834** its own private copy of the content of the [sqlite3_mem_methods] structure 1835** before the [sqlite3_config()] call returns.</dd> 1836** 1837** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1838** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1839** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1840** The [sqlite3_mem_methods] 1841** structure is filled with the currently defined memory allocation routines.)^ 1842** This option can be used to overload the default memory allocation 1843** routines with a wrapper that simulations memory allocation failure or 1844** tracks memory usage, for example. </dd> 1845** 1846** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> 1847** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of 1848** type int, interpreted as a boolean, which if true provides a hint to 1849** SQLite that it should avoid large memory allocations if possible. 1850** SQLite will run faster if it is free to make large memory allocations, 1851** but some application might prefer to run slower in exchange for 1852** guarantees about memory fragmentation that are possible if large 1853** allocations are avoided. This hint is normally off. 1854** </dd> 1855** 1856** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1857** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1858** interpreted as a boolean, which enables or disables the collection of 1859** memory allocation statistics. ^(When memory allocation statistics are 1860** disabled, the following SQLite interfaces become non-operational: 1861** <ul> 1862** <li> [sqlite3_hard_heap_limit64()] 1863** <li> [sqlite3_memory_used()] 1864** <li> [sqlite3_memory_highwater()] 1865** <li> [sqlite3_soft_heap_limit64()] 1866** <li> [sqlite3_status64()] 1867** </ul>)^ 1868** ^Memory allocation statistics are enabled by default unless SQLite is 1869** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1870** allocation statistics are disabled by default. 1871** </dd> 1872** 1873** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1874** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1875** </dd> 1876** 1877** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1878** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1879** that SQLite can use for the database page cache with the default page 1880** cache implementation. 1881** This configuration option is a no-op if an application-defined page 1882** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1883** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1884** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1885** and the number of cache lines (N). 1886** The sz argument should be the size of the largest database page 1887** (a power of two between 512 and 65536) plus some extra bytes for each 1888** page header. ^The number of extra bytes needed by the page header 1889** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1890** ^It is harmless, apart from the wasted memory, 1891** for the sz parameter to be larger than necessary. The pMem 1892** argument must be either a NULL pointer or a pointer to an 8-byte 1893** aligned block of memory of at least sz*N bytes, otherwise 1894** subsequent behavior is undefined. 1895** ^When pMem is not NULL, SQLite will strive to use the memory provided 1896** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1897** a page cache line is larger than sz bytes or if all of the pMem buffer 1898** is exhausted. 1899** ^If pMem is NULL and N is non-zero, then each database connection 1900** does an initial bulk allocation for page cache memory 1901** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1902** of -1024*N bytes if N is negative, . ^If additional 1903** page cache memory is needed beyond what is provided by the initial 1904** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1905** additional cache line. </dd> 1906** 1907** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1908** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1909** that SQLite will use for all of its dynamic memory allocation needs 1910** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 1911** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1912** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1913** [SQLITE_ERROR] if invoked otherwise. 1914** ^There are three arguments to SQLITE_CONFIG_HEAP: 1915** An 8-byte aligned pointer to the memory, 1916** the number of bytes in the memory buffer, and the minimum allocation size. 1917** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1918** to using its default memory allocator (the system malloc() implementation), 1919** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1920** memory pointer is not NULL then the alternative memory 1921** allocator is engaged to handle all of SQLites memory allocation needs. 1922** The first pointer (the memory pointer) must be aligned to an 8-byte 1923** boundary or subsequent behavior of SQLite will be undefined. 1924** The minimum allocation size is capped at 2**12. Reasonable values 1925** for the minimum allocation size are 2**5 through 2**8.</dd> 1926** 1927** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1928** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1929** pointer to an instance of the [sqlite3_mutex_methods] structure. 1930** The argument specifies alternative low-level mutex routines to be used 1931** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1932** the content of the [sqlite3_mutex_methods] structure before the call to 1933** [sqlite3_config()] returns. ^If SQLite is compiled with 1934** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1935** the entire mutexing subsystem is omitted from the build and hence calls to 1936** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1937** return [SQLITE_ERROR].</dd> 1938** 1939** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1940** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1941** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1942** [sqlite3_mutex_methods] 1943** structure is filled with the currently defined mutex routines.)^ 1944** This option can be used to overload the default mutex allocation 1945** routines with a wrapper used to track mutex usage for performance 1946** profiling or testing, for example. ^If SQLite is compiled with 1947** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1948** the entire mutexing subsystem is omitted from the build and hence calls to 1949** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1950** return [SQLITE_ERROR].</dd> 1951** 1952** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1953** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1954** the default size of lookaside memory on each [database connection]. 1955** The first argument is the 1956** size of each lookaside buffer slot and the second is the number of 1957** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1958** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1959** option to [sqlite3_db_config()] can be used to change the lookaside 1960** configuration on individual connections.)^ </dd> 1961** 1962** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1963** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1964** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1965** the interface to a custom page cache implementation.)^ 1966** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1967** 1968** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1969** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1970** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1971** the current page cache implementation into that object.)^ </dd> 1972** 1973** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1974** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1975** global [error log]. 1976** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1977** function with a call signature of void(*)(void*,int,const char*), 1978** and a pointer to void. ^If the function pointer is not NULL, it is 1979** invoked by [sqlite3_log()] to process each logging event. ^If the 1980** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1981** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1982** passed through as the first parameter to the application-defined logger 1983** function whenever that function is invoked. ^The second parameter to 1984** the logger function is a copy of the first parameter to the corresponding 1985** [sqlite3_log()] call and is intended to be a [result code] or an 1986** [extended result code]. ^The third parameter passed to the logger is 1987** log message after formatting via [sqlite3_snprintf()]. 1988** The SQLite logging interface is not reentrant; the logger function 1989** supplied by the application must not invoke any SQLite interface. 1990** In a multi-threaded application, the application-defined logger 1991** function must be threadsafe. </dd> 1992** 1993** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1994** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1995** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1996** then URI handling is globally disabled.)^ ^If URI handling is globally 1997** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1998** [sqlite3_open16()] or 1999** specified as part of [ATTACH] commands are interpreted as URIs, regardless 2000** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 2001** connection is opened. ^If it is globally disabled, filenames are 2002** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 2003** database connection is opened. ^(By default, URI handling is globally 2004** disabled. The default value may be changed by compiling with the 2005** [SQLITE_USE_URI] symbol defined.)^ 2006** 2007** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 2008** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 2009** argument which is interpreted as a boolean in order to enable or disable 2010** the use of covering indices for full table scans in the query optimizer. 2011** ^The default setting is determined 2012** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 2013** if that compile-time option is omitted. 2014** The ability to disable the use of covering indices for full table scans 2015** is because some incorrectly coded legacy applications might malfunction 2016** when the optimization is enabled. Providing the ability to 2017** disable the optimization allows the older, buggy application code to work 2018** without change even with newer versions of SQLite. 2019** 2020** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 2021** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 2022** <dd> These options are obsolete and should not be used by new code. 2023** They are retained for backwards compatibility but are now no-ops. 2024** </dd> 2025** 2026** [[SQLITE_CONFIG_SQLLOG]] 2027** <dt>SQLITE_CONFIG_SQLLOG 2028** <dd>This option is only available if sqlite is compiled with the 2029** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 2030** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 2031** The second should be of type (void*). The callback is invoked by the library 2032** in three separate circumstances, identified by the value passed as the 2033** fourth parameter. If the fourth parameter is 0, then the database connection 2034** passed as the second argument has just been opened. The third argument 2035** points to a buffer containing the name of the main database file. If the 2036** fourth parameter is 1, then the SQL statement that the third parameter 2037** points to has just been executed. Or, if the fourth parameter is 2, then 2038** the connection being passed as the second parameter is being closed. The 2039** third parameter is passed NULL In this case. An example of using this 2040** configuration option can be seen in the "test_sqllog.c" source file in 2041** the canonical SQLite source tree.</dd> 2042** 2043** [[SQLITE_CONFIG_MMAP_SIZE]] 2044** <dt>SQLITE_CONFIG_MMAP_SIZE 2045** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 2046** that are the default mmap size limit (the default setting for 2047** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 2048** ^The default setting can be overridden by each database connection using 2049** either the [PRAGMA mmap_size] command, or by using the 2050** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 2051** will be silently truncated if necessary so that it does not exceed the 2052** compile-time maximum mmap size set by the 2053** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 2054** ^If either argument to this option is negative, then that argument is 2055** changed to its compile-time default. 2056** 2057** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 2058** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 2059** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 2060** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 2061** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 2062** that specifies the maximum size of the created heap. 2063** 2064** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 2065** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 2066** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 2067** is a pointer to an integer and writes into that integer the number of extra 2068** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 2069** The amount of extra space required can change depending on the compiler, 2070** target platform, and SQLite version. 2071** 2072** [[SQLITE_CONFIG_PMASZ]] 2073** <dt>SQLITE_CONFIG_PMASZ 2074** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 2075** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 2076** sorter to that integer. The default minimum PMA Size is set by the 2077** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 2078** to help with sort operations when multithreaded sorting 2079** is enabled (using the [PRAGMA threads] command) and the amount of content 2080** to be sorted exceeds the page size times the minimum of the 2081** [PRAGMA cache_size] setting and this value. 2082** 2083** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 2084** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 2085** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 2086** becomes the [statement journal] spill-to-disk threshold. 2087** [Statement journals] are held in memory until their size (in bytes) 2088** exceeds this threshold, at which point they are written to disk. 2089** Or if the threshold is -1, statement journals are always held 2090** exclusively in memory. 2091** Since many statement journals never become large, setting the spill 2092** threshold to a value such as 64KiB can greatly reduce the amount of 2093** I/O required to support statement rollback. 2094** The default value for this setting is controlled by the 2095** [SQLITE_STMTJRNL_SPILL] compile-time option. 2096** 2097** [[SQLITE_CONFIG_SORTERREF_SIZE]] 2098** <dt>SQLITE_CONFIG_SORTERREF_SIZE 2099** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter 2100** of type (int) - the new value of the sorter-reference size threshold. 2101** Usually, when SQLite uses an external sort to order records according 2102** to an ORDER BY clause, all fields required by the caller are present in the 2103** sorted records. However, if SQLite determines based on the declared type 2104** of a table column that its values are likely to be very large - larger 2105** than the configured sorter-reference size threshold - then a reference 2106** is stored in each sorted record and the required column values loaded 2107** from the database as records are returned in sorted order. The default 2108** value for this option is to never use this optimization. Specifying a 2109** negative value for this option restores the default behaviour. 2110** This option is only available if SQLite is compiled with the 2111** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option. 2112** 2113** [[SQLITE_CONFIG_MEMDB_MAXSIZE]] 2114** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE 2115** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter 2116** [sqlite3_int64] parameter which is the default maximum size for an in-memory 2117** database created using [sqlite3_deserialize()]. This default maximum 2118** size can be adjusted up or down for individual databases using the 2119** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this 2120** configuration setting is never used, then the default maximum is determined 2121** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that 2122** compile-time option is not set, then the default maximum is 1073741824. 2123** </dl> 2124*/ 2125#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 2126#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 2127#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 2128#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 2129#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 2130#define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 2131#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 2132#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 2133#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 2134#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 2135#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 2136/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 2137#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 2138#define SQLITE_CONFIG_PCACHE 14 /* no-op */ 2139#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 2140#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 2141#define SQLITE_CONFIG_URI 17 /* int */ 2142#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 2143#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 2144#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 2145#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 2146#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 2147#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 2148#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 2149#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 2150#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 2151#define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ 2152#define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */ 2153#define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */ 2154 2155/* 2156** CAPI3REF: Database Connection Configuration Options 2157** 2158** These constants are the available integer configuration options that 2159** can be passed as the second argument to the [sqlite3_db_config()] interface. 2160** 2161** New configuration options may be added in future releases of SQLite. 2162** Existing configuration options might be discontinued. Applications 2163** should check the return code from [sqlite3_db_config()] to make sure that 2164** the call worked. ^The [sqlite3_db_config()] interface will return a 2165** non-zero [error code] if a discontinued or unsupported configuration option 2166** is invoked. 2167** 2168** <dl> 2169** [[SQLITE_DBCONFIG_LOOKASIDE]] 2170** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 2171** <dd> ^This option takes three additional arguments that determine the 2172** [lookaside memory allocator] configuration for the [database connection]. 2173** ^The first argument (the third parameter to [sqlite3_db_config()] is a 2174** pointer to a memory buffer to use for lookaside memory. 2175** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 2176** may be NULL in which case SQLite will allocate the 2177** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 2178** size of each lookaside buffer slot. ^The third argument is the number of 2179** slots. The size of the buffer in the first argument must be greater than 2180** or equal to the product of the second and third arguments. The buffer 2181** must be aligned to an 8-byte boundary. ^If the second argument to 2182** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 2183** rounded down to the next smaller multiple of 8. ^(The lookaside memory 2184** configuration for a database connection can only be changed when that 2185** connection is not currently using lookaside memory, or in other words 2186** when the "current value" returned by 2187** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 2188** Any attempt to change the lookaside memory configuration when lookaside 2189** memory is in use leaves the configuration unchanged and returns 2190** [SQLITE_BUSY].)^</dd> 2191** 2192** [[SQLITE_DBCONFIG_ENABLE_FKEY]] 2193** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 2194** <dd> ^This option is used to enable or disable the enforcement of 2195** [foreign key constraints]. There should be two additional arguments. 2196** The first argument is an integer which is 0 to disable FK enforcement, 2197** positive to enable FK enforcement or negative to leave FK enforcement 2198** unchanged. The second parameter is a pointer to an integer into which 2199** is written 0 or 1 to indicate whether FK enforcement is off or on 2200** following this call. The second parameter may be a NULL pointer, in 2201** which case the FK enforcement setting is not reported back. </dd> 2202** 2203** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]] 2204** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 2205** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 2206** There should be two additional arguments. 2207** The first argument is an integer which is 0 to disable triggers, 2208** positive to enable triggers or negative to leave the setting unchanged. 2209** The second parameter is a pointer to an integer into which 2210** is written 0 or 1 to indicate whether triggers are disabled or enabled 2211** following this call. The second parameter may be a NULL pointer, in 2212** which case the trigger setting is not reported back. 2213** 2214** <p>Originally this option disabled all triggers. ^(However, since 2215** SQLite version 3.35.0, TEMP triggers are still allowed even if 2216** this option is off. So, in other words, this option now only disables 2217** triggers in the main database schema or in the schemas of ATTACH-ed 2218** databases.)^ </dd> 2219** 2220** [[SQLITE_DBCONFIG_ENABLE_VIEW]] 2221** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt> 2222** <dd> ^This option is used to enable or disable [CREATE VIEW | views]. 2223** There should be two additional arguments. 2224** The first argument is an integer which is 0 to disable views, 2225** positive to enable views or negative to leave the setting unchanged. 2226** The second parameter is a pointer to an integer into which 2227** is written 0 or 1 to indicate whether views are disabled or enabled 2228** following this call. The second parameter may be a NULL pointer, in 2229** which case the view setting is not reported back. 2230** 2231** <p>Originally this option disabled all views. ^(However, since 2232** SQLite version 3.35.0, TEMP views are still allowed even if 2233** this option is off. So, in other words, this option now only disables 2234** views in the main database schema or in the schemas of ATTACH-ed 2235** databases.)^ </dd> 2236** 2237** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]] 2238** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2239** <dd> ^This option is used to enable or disable the 2240** [fts3_tokenizer()] function which is part of the 2241** [FTS3] full-text search engine extension. 2242** There should be two additional arguments. 2243** The first argument is an integer which is 0 to disable fts3_tokenizer() or 2244** positive to enable fts3_tokenizer() or negative to leave the setting 2245** unchanged. 2246** The second parameter is a pointer to an integer into which 2247** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 2248** following this call. The second parameter may be a NULL pointer, in 2249** which case the new setting is not reported back. </dd> 2250** 2251** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]] 2252** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2253** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2254** interface independently of the [load_extension()] SQL function. 2255** The [sqlite3_enable_load_extension()] API enables or disables both the 2256** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2257** There should be two additional arguments. 2258** When the first argument to this interface is 1, then only the C-API is 2259** enabled and the SQL function remains disabled. If the first argument to 2260** this interface is 0, then both the C-API and the SQL function are disabled. 2261** If the first argument is -1, then no changes are made to state of either the 2262** C-API or the SQL function. 2263** The second parameter is a pointer to an integer into which 2264** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2265** is disabled or enabled following this call. The second parameter may 2266** be a NULL pointer, in which case the new setting is not reported back. 2267** </dd> 2268** 2269** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2270** <dd> ^This option is used to change the name of the "main" database 2271** schema. ^The sole argument is a pointer to a constant UTF8 string 2272** which will become the new schema name in place of "main". ^SQLite 2273** does not make a copy of the new main schema name string, so the application 2274** must ensure that the argument passed into this DBCONFIG option is unchanged 2275** until after the database connection closes. 2276** </dd> 2277** 2278** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]] 2279** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2280** <dd> Usually, when a database in wal mode is closed or detached from a 2281** database handle, SQLite checks if this will mean that there are now no 2282** connections at all to the database. If so, it performs a checkpoint 2283** operation before closing the connection. This option may be used to 2284** override this behaviour. The first parameter passed to this operation 2285** is an integer - positive to disable checkpoints-on-close, or zero (the 2286** default) to enable them, and negative to leave the setting unchanged. 2287** The second parameter is a pointer to an integer 2288** into which is written 0 or 1 to indicate whether checkpoints-on-close 2289** have been disabled - 0 if they are not disabled, 1 if they are. 2290** </dd> 2291** 2292** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> 2293** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates 2294** the [query planner stability guarantee] (QPSG). When the QPSG is active, 2295** a single SQL query statement will always use the same algorithm regardless 2296** of values of [bound parameters].)^ The QPSG disables some query optimizations 2297** that look at the values of bound parameters, which can make some queries 2298** slower. But the QPSG has the advantage of more predictable behavior. With 2299** the QPSG active, SQLite will always use the same query plan in the field as 2300** was used during testing in the lab. 2301** The first argument to this setting is an integer which is 0 to disable 2302** the QPSG, positive to enable QPSG, or negative to leave the setting 2303** unchanged. The second parameter is a pointer to an integer into which 2304** is written 0 or 1 to indicate whether the QPSG is disabled or enabled 2305** following this call. 2306** </dd> 2307** 2308** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt> 2309** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 2310** include output for any operations performed by trigger programs. This 2311** option is used to set or clear (the default) a flag that governs this 2312** behavior. The first parameter passed to this operation is an integer - 2313** positive to enable output for trigger programs, or zero to disable it, 2314** or negative to leave the setting unchanged. 2315** The second parameter is a pointer to an integer into which is written 2316** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 2317** it is not disabled, 1 if it is. 2318** </dd> 2319** 2320** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt> 2321** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run 2322** [VACUUM] in order to reset a database back to an empty database 2323** with no schema and no content. The following process works even for 2324** a badly corrupted database file: 2325** <ol> 2326** <li> If the database connection is newly opened, make sure it has read the 2327** database schema by preparing then discarding some query against the 2328** database, or calling sqlite3_table_column_metadata(), ignoring any 2329** errors. This step is only necessary if the application desires to keep 2330** the database in WAL mode after the reset if it was in WAL mode before 2331** the reset. 2332** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0); 2333** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0); 2334** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0); 2335** </ol> 2336** Because resetting a database is destructive and irreversible, the 2337** process requires the use of this obscure API and multiple steps to help 2338** ensure that it does not happen by accident. 2339** 2340** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt> 2341** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the 2342** "defensive" flag for a database connection. When the defensive 2343** flag is enabled, language features that allow ordinary SQL to 2344** deliberately corrupt the database file are disabled. The disabled 2345** features include but are not limited to the following: 2346** <ul> 2347** <li> The [PRAGMA writable_schema=ON] statement. 2348** <li> The [PRAGMA journal_mode=OFF] statement. 2349** <li> The [PRAGMA schema_version=N] statement. 2350** <li> Writes to the [sqlite_dbpage] virtual table. 2351** <li> Direct writes to [shadow tables]. 2352** </ul> 2353** </dd> 2354** 2355** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt> 2356** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the 2357** "writable_schema" flag. This has the same effect and is logically equivalent 2358** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF]. 2359** The first argument to this setting is an integer which is 0 to disable 2360** the writable_schema, positive to enable writable_schema, or negative to 2361** leave the setting unchanged. The second parameter is a pointer to an 2362** integer into which is written 0 or 1 to indicate whether the writable_schema 2363** is enabled or disabled following this call. 2364** </dd> 2365** 2366** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]] 2367** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt> 2368** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates 2369** the legacy behavior of the [ALTER TABLE RENAME] command such it 2370** behaves as it did prior to [version 3.24.0] (2018-06-04). See the 2371** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for 2372** additional information. This feature can also be turned on and off 2373** using the [PRAGMA legacy_alter_table] statement. 2374** </dd> 2375** 2376** [[SQLITE_DBCONFIG_DQS_DML]] 2377** <dt>SQLITE_DBCONFIG_DQS_DML</td> 2378** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates 2379** the legacy [double-quoted string literal] misfeature for DML statements 2380** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The 2381** default value of this setting is determined by the [-DSQLITE_DQS] 2382** compile-time option. 2383** </dd> 2384** 2385** [[SQLITE_DBCONFIG_DQS_DDL]] 2386** <dt>SQLITE_DBCONFIG_DQS_DDL</td> 2387** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates 2388** the legacy [double-quoted string literal] misfeature for DDL statements, 2389** such as CREATE TABLE and CREATE INDEX. The 2390** default value of this setting is determined by the [-DSQLITE_DQS] 2391** compile-time option. 2392** </dd> 2393** 2394** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]] 2395** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</td> 2396** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to 2397** assume that database schemas are untainted by malicious content. 2398** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite 2399** takes additional defensive steps to protect the application from harm 2400** including: 2401** <ul> 2402** <li> Prohibit the use of SQL functions inside triggers, views, 2403** CHECK constraints, DEFAULT clauses, expression indexes, 2404** partial indexes, or generated columns 2405** unless those functions are tagged with [SQLITE_INNOCUOUS]. 2406** <li> Prohibit the use of virtual tables inside of triggers or views 2407** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS]. 2408** </ul> 2409** This setting defaults to "on" for legacy compatibility, however 2410** all applications are advised to turn it off if possible. This setting 2411** can also be controlled using the [PRAGMA trusted_schema] statement. 2412** </dd> 2413** 2414** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]] 2415** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</td> 2416** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates 2417** the legacy file format flag. When activated, this flag causes all newly 2418** created database file to have a schema format version number (the 4-byte 2419** integer found at offset 44 into the database header) of 1. This in turn 2420** means that the resulting database file will be readable and writable by 2421** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting, 2422** newly created databases are generally not understandable by SQLite versions 2423** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there 2424** is now scarcely any need to generated database files that are compatible 2425** all the way back to version 3.0.0, and so this setting is of little 2426** practical use, but is provided so that SQLite can continue to claim the 2427** ability to generate new database files that are compatible with version 2428** 3.0.0. 2429** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on, 2430** the [VACUUM] command will fail with an obscure error when attempting to 2431** process a table with generated columns and a descending index. This is 2432** not considered a bug since SQLite versions 3.3.0 and earlier do not support 2433** either generated columns or decending indexes. 2434** </dd> 2435** </dl> 2436*/ 2437#define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2438#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2439#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2440#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2441#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2442#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2443#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2444#define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ 2445#define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ 2446#define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */ 2447#define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */ 2448#define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */ 2449#define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */ 2450#define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */ 2451#define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */ 2452#define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */ 2453#define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */ 2454#define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */ 2455#define SQLITE_DBCONFIG_MAX 1017 /* Largest DBCONFIG */ 2456 2457/* 2458** CAPI3REF: Enable Or Disable Extended Result Codes 2459** METHOD: sqlite3 2460** 2461** ^The sqlite3_extended_result_codes() routine enables or disables the 2462** [extended result codes] feature of SQLite. ^The extended result 2463** codes are disabled by default for historical compatibility. 2464*/ 2465SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 2466 2467/* 2468** CAPI3REF: Last Insert Rowid 2469** METHOD: sqlite3 2470** 2471** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2472** has a unique 64-bit signed 2473** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2474** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2475** names are not also used by explicitly declared columns. ^If 2476** the table has a column of type [INTEGER PRIMARY KEY] then that column 2477** is another alias for the rowid. 2478** 2479** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2480** the most recent successful [INSERT] into a rowid table or [virtual table] 2481** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2482** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2483** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2484** zero. 2485** 2486** As well as being set automatically as rows are inserted into database 2487** tables, the value returned by this function may be set explicitly by 2488** [sqlite3_set_last_insert_rowid()] 2489** 2490** Some virtual table implementations may INSERT rows into rowid tables as 2491** part of committing a transaction (e.g. to flush data accumulated in memory 2492** to disk). In this case subsequent calls to this function return the rowid 2493** associated with these internal INSERT operations, which leads to 2494** unintuitive results. Virtual table implementations that do write to rowid 2495** tables in this way can avoid this problem by restoring the original 2496** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2497** control to the user. 2498** 2499** ^(If an [INSERT] occurs within a trigger then this routine will 2500** return the [rowid] of the inserted row as long as the trigger is 2501** running. Once the trigger program ends, the value returned 2502** by this routine reverts to what it was before the trigger was fired.)^ 2503** 2504** ^An [INSERT] that fails due to a constraint violation is not a 2505** successful [INSERT] and does not change the value returned by this 2506** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2507** and INSERT OR ABORT make no changes to the return value of this 2508** routine when their insertion fails. ^(When INSERT OR REPLACE 2509** encounters a constraint violation, it does not fail. The 2510** INSERT continues to completion after deleting rows that caused 2511** the constraint problem so INSERT OR REPLACE will always change 2512** the return value of this interface.)^ 2513** 2514** ^For the purposes of this routine, an [INSERT] is considered to 2515** be successful even if it is subsequently rolled back. 2516** 2517** This function is accessible to SQL statements via the 2518** [last_insert_rowid() SQL function]. 2519** 2520** If a separate thread performs a new [INSERT] on the same 2521** database connection while the [sqlite3_last_insert_rowid()] 2522** function is running and thus changes the last insert [rowid], 2523** then the value returned by [sqlite3_last_insert_rowid()] is 2524** unpredictable and might not equal either the old or the new 2525** last insert [rowid]. 2526*/ 2527SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2528 2529/* 2530** CAPI3REF: Set the Last Insert Rowid value. 2531** METHOD: sqlite3 2532** 2533** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2534** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2535** without inserting a row into the database. 2536*/ 2537SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2538 2539/* 2540** CAPI3REF: Count The Number Of Rows Modified 2541** METHOD: sqlite3 2542** 2543** ^These functions return the number of rows modified, inserted or 2544** deleted by the most recently completed INSERT, UPDATE or DELETE 2545** statement on the database connection specified by the only parameter. 2546** The two functions are identical except for the type of the return value 2547** and that if the number of rows modified by the most recent INSERT, UPDATE 2548** or DELETE is greater than the maximum value supported by type "int", then 2549** the return value of sqlite3_changes() is undefined. ^Executing any other 2550** type of SQL statement does not modify the value returned by these functions. 2551** 2552** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2553** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2554** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2555** 2556** Changes to a view that are intercepted by 2557** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2558** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2559** DELETE statement run on a view is always zero. Only changes made to real 2560** tables are counted. 2561** 2562** Things are more complicated if the sqlite3_changes() function is 2563** executed while a trigger program is running. This may happen if the 2564** program uses the [changes() SQL function], or if some other callback 2565** function invokes sqlite3_changes() directly. Essentially: 2566** 2567** <ul> 2568** <li> ^(Before entering a trigger program the value returned by 2569** sqlite3_changes() function is saved. After the trigger program 2570** has finished, the original value is restored.)^ 2571** 2572** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2573** statement sets the value returned by sqlite3_changes() 2574** upon completion as normal. Of course, this value will not include 2575** any changes performed by sub-triggers, as the sqlite3_changes() 2576** value will be saved and restored after each sub-trigger has run.)^ 2577** </ul> 2578** 2579** ^This means that if the changes() SQL function (or similar) is used 2580** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2581** returns the value as set when the calling statement began executing. 2582** ^If it is used by the second or subsequent such statement within a trigger 2583** program, the value returned reflects the number of rows modified by the 2584** previous INSERT, UPDATE or DELETE statement within the same trigger. 2585** 2586** If a separate thread makes changes on the same database connection 2587** while [sqlite3_changes()] is running then the value returned 2588** is unpredictable and not meaningful. 2589** 2590** See also: 2591** <ul> 2592** <li> the [sqlite3_total_changes()] interface 2593** <li> the [count_changes pragma] 2594** <li> the [changes() SQL function] 2595** <li> the [data_version pragma] 2596** </ul> 2597*/ 2598SQLITE_API int sqlite3_changes(sqlite3*); 2599SQLITE_API sqlite3_int64 sqlite3_changes64(sqlite3*); 2600 2601/* 2602** CAPI3REF: Total Number Of Rows Modified 2603** METHOD: sqlite3 2604** 2605** ^These functions return the total number of rows inserted, modified or 2606** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2607** since the database connection was opened, including those executed as 2608** part of trigger programs. The two functions are identical except for the 2609** type of the return value and that if the number of rows modified by the 2610** connection exceeds the maximum value supported by type "int", then 2611** the return value of sqlite3_total_changes() is undefined. ^Executing 2612** any other type of SQL statement does not affect the value returned by 2613** sqlite3_total_changes(). 2614** 2615** ^Changes made as part of [foreign key actions] are included in the 2616** count, but those made as part of REPLACE constraint resolution are 2617** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2618** are not counted. 2619** 2620** The [sqlite3_total_changes(D)] interface only reports the number 2621** of rows that changed due to SQL statement run against database 2622** connection D. Any changes by other database connections are ignored. 2623** To detect changes against a database file from other database 2624** connections use the [PRAGMA data_version] command or the 2625** [SQLITE_FCNTL_DATA_VERSION] [file control]. 2626** 2627** If a separate thread makes changes on the same database connection 2628** while [sqlite3_total_changes()] is running then the value 2629** returned is unpredictable and not meaningful. 2630** 2631** See also: 2632** <ul> 2633** <li> the [sqlite3_changes()] interface 2634** <li> the [count_changes pragma] 2635** <li> the [changes() SQL function] 2636** <li> the [data_version pragma] 2637** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control] 2638** </ul> 2639*/ 2640SQLITE_API int sqlite3_total_changes(sqlite3*); 2641SQLITE_API sqlite3_int64 sqlite3_total_changes64(sqlite3*); 2642 2643/* 2644** CAPI3REF: Interrupt A Long-Running Query 2645** METHOD: sqlite3 2646** 2647** ^This function causes any pending database operation to abort and 2648** return at its earliest opportunity. This routine is typically 2649** called in response to a user action such as pressing "Cancel" 2650** or Ctrl-C where the user wants a long query operation to halt 2651** immediately. 2652** 2653** ^It is safe to call this routine from a thread different from the 2654** thread that is currently running the database operation. But it 2655** is not safe to call this routine with a [database connection] that 2656** is closed or might close before sqlite3_interrupt() returns. 2657** 2658** ^If an SQL operation is very nearly finished at the time when 2659** sqlite3_interrupt() is called, then it might not have an opportunity 2660** to be interrupted and might continue to completion. 2661** 2662** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2663** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2664** that is inside an explicit transaction, then the entire transaction 2665** will be rolled back automatically. 2666** 2667** ^The sqlite3_interrupt(D) call is in effect until all currently running 2668** SQL statements on [database connection] D complete. ^Any new SQL statements 2669** that are started after the sqlite3_interrupt() call and before the 2670** running statement count reaches zero are interrupted as if they had been 2671** running prior to the sqlite3_interrupt() call. ^New SQL statements 2672** that are started after the running statement count reaches zero are 2673** not effected by the sqlite3_interrupt(). 2674** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2675** SQL statements is a no-op and has no effect on SQL statements 2676** that are started after the sqlite3_interrupt() call returns. 2677*/ 2678SQLITE_API void sqlite3_interrupt(sqlite3*); 2679 2680/* 2681** CAPI3REF: Determine If An SQL Statement Is Complete 2682** 2683** These routines are useful during command-line input to determine if the 2684** currently entered text seems to form a complete SQL statement or 2685** if additional input is needed before sending the text into 2686** SQLite for parsing. ^These routines return 1 if the input string 2687** appears to be a complete SQL statement. ^A statement is judged to be 2688** complete if it ends with a semicolon token and is not a prefix of a 2689** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2690** string literals or quoted identifier names or comments are not 2691** independent tokens (they are part of the token in which they are 2692** embedded) and thus do not count as a statement terminator. ^Whitespace 2693** and comments that follow the final semicolon are ignored. 2694** 2695** ^These routines return 0 if the statement is incomplete. ^If a 2696** memory allocation fails, then SQLITE_NOMEM is returned. 2697** 2698** ^These routines do not parse the SQL statements thus 2699** will not detect syntactically incorrect SQL. 2700** 2701** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2702** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2703** automatically by sqlite3_complete16(). If that initialization fails, 2704** then the return value from sqlite3_complete16() will be non-zero 2705** regardless of whether or not the input SQL is complete.)^ 2706** 2707** The input to [sqlite3_complete()] must be a zero-terminated 2708** UTF-8 string. 2709** 2710** The input to [sqlite3_complete16()] must be a zero-terminated 2711** UTF-16 string in native byte order. 2712*/ 2713SQLITE_API int sqlite3_complete(const char *sql); 2714SQLITE_API int sqlite3_complete16(const void *sql); 2715 2716/* 2717** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2718** KEYWORDS: {busy-handler callback} {busy handler} 2719** METHOD: sqlite3 2720** 2721** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2722** that might be invoked with argument P whenever 2723** an attempt is made to access a database table associated with 2724** [database connection] D when another thread 2725** or process has the table locked. 2726** The sqlite3_busy_handler() interface is used to implement 2727** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2728** 2729** ^If the busy callback is NULL, then [SQLITE_BUSY] 2730** is returned immediately upon encountering the lock. ^If the busy callback 2731** is not NULL, then the callback might be invoked with two arguments. 2732** 2733** ^The first argument to the busy handler is a copy of the void* pointer which 2734** is the third argument to sqlite3_busy_handler(). ^The second argument to 2735** the busy handler callback is the number of times that the busy handler has 2736** been invoked previously for the same locking event. ^If the 2737** busy callback returns 0, then no additional attempts are made to 2738** access the database and [SQLITE_BUSY] is returned 2739** to the application. 2740** ^If the callback returns non-zero, then another attempt 2741** is made to access the database and the cycle repeats. 2742** 2743** The presence of a busy handler does not guarantee that it will be invoked 2744** when there is lock contention. ^If SQLite determines that invoking the busy 2745** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2746** to the application instead of invoking the 2747** busy handler. 2748** Consider a scenario where one process is holding a read lock that 2749** it is trying to promote to a reserved lock and 2750** a second process is holding a reserved lock that it is trying 2751** to promote to an exclusive lock. The first process cannot proceed 2752** because it is blocked by the second and the second process cannot 2753** proceed because it is blocked by the first. If both processes 2754** invoke the busy handlers, neither will make any progress. Therefore, 2755** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2756** will induce the first process to release its read lock and allow 2757** the second process to proceed. 2758** 2759** ^The default busy callback is NULL. 2760** 2761** ^(There can only be a single busy handler defined for each 2762** [database connection]. Setting a new busy handler clears any 2763** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2764** or evaluating [PRAGMA busy_timeout=N] will change the 2765** busy handler and thus clear any previously set busy handler. 2766** 2767** The busy callback should not take any actions which modify the 2768** database connection that invoked the busy handler. In other words, 2769** the busy handler is not reentrant. Any such actions 2770** result in undefined behavior. 2771** 2772** A busy handler must not close the database connection 2773** or [prepared statement] that invoked the busy handler. 2774*/ 2775SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2776 2777/* 2778** CAPI3REF: Set A Busy Timeout 2779** METHOD: sqlite3 2780** 2781** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2782** for a specified amount of time when a table is locked. ^The handler 2783** will sleep multiple times until at least "ms" milliseconds of sleeping 2784** have accumulated. ^After at least "ms" milliseconds of sleeping, 2785** the handler returns 0 which causes [sqlite3_step()] to return 2786** [SQLITE_BUSY]. 2787** 2788** ^Calling this routine with an argument less than or equal to zero 2789** turns off all busy handlers. 2790** 2791** ^(There can only be a single busy handler for a particular 2792** [database connection] at any given moment. If another busy handler 2793** was defined (using [sqlite3_busy_handler()]) prior to calling 2794** this routine, that other busy handler is cleared.)^ 2795** 2796** See also: [PRAGMA busy_timeout] 2797*/ 2798SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 2799 2800/* 2801** CAPI3REF: Convenience Routines For Running Queries 2802** METHOD: sqlite3 2803** 2804** This is a legacy interface that is preserved for backwards compatibility. 2805** Use of this interface is not recommended. 2806** 2807** Definition: A <b>result table</b> is memory data structure created by the 2808** [sqlite3_get_table()] interface. A result table records the 2809** complete query results from one or more queries. 2810** 2811** The table conceptually has a number of rows and columns. But 2812** these numbers are not part of the result table itself. These 2813** numbers are obtained separately. Let N be the number of rows 2814** and M be the number of columns. 2815** 2816** A result table is an array of pointers to zero-terminated UTF-8 strings. 2817** There are (N+1)*M elements in the array. The first M pointers point 2818** to zero-terminated strings that contain the names of the columns. 2819** The remaining entries all point to query results. NULL values result 2820** in NULL pointers. All other values are in their UTF-8 zero-terminated 2821** string representation as returned by [sqlite3_column_text()]. 2822** 2823** A result table might consist of one or more memory allocations. 2824** It is not safe to pass a result table directly to [sqlite3_free()]. 2825** A result table should be deallocated using [sqlite3_free_table()]. 2826** 2827** ^(As an example of the result table format, suppose a query result 2828** is as follows: 2829** 2830** <blockquote><pre> 2831** Name | Age 2832** ----------------------- 2833** Alice | 43 2834** Bob | 28 2835** Cindy | 21 2836** </pre></blockquote> 2837** 2838** There are two columns (M==2) and three rows (N==3). Thus the 2839** result table has 8 entries. Suppose the result table is stored 2840** in an array named azResult. Then azResult holds this content: 2841** 2842** <blockquote><pre> 2843** azResult[0] = "Name"; 2844** azResult[1] = "Age"; 2845** azResult[2] = "Alice"; 2846** azResult[3] = "43"; 2847** azResult[4] = "Bob"; 2848** azResult[5] = "28"; 2849** azResult[6] = "Cindy"; 2850** azResult[7] = "21"; 2851** </pre></blockquote>)^ 2852** 2853** ^The sqlite3_get_table() function evaluates one or more 2854** semicolon-separated SQL statements in the zero-terminated UTF-8 2855** string of its 2nd parameter and returns a result table to the 2856** pointer given in its 3rd parameter. 2857** 2858** After the application has finished with the result from sqlite3_get_table(), 2859** it must pass the result table pointer to sqlite3_free_table() in order to 2860** release the memory that was malloced. Because of the way the 2861** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2862** function must not try to call [sqlite3_free()] directly. Only 2863** [sqlite3_free_table()] is able to release the memory properly and safely. 2864** 2865** The sqlite3_get_table() interface is implemented as a wrapper around 2866** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2867** to any internal data structures of SQLite. It uses only the public 2868** interface defined here. As a consequence, errors that occur in the 2869** wrapper layer outside of the internal [sqlite3_exec()] call are not 2870** reflected in subsequent calls to [sqlite3_errcode()] or 2871** [sqlite3_errmsg()]. 2872*/ 2873SQLITE_API int sqlite3_get_table( 2874 sqlite3 *db, /* An open database */ 2875 const char *zSql, /* SQL to be evaluated */ 2876 char ***pazResult, /* Results of the query */ 2877 int *pnRow, /* Number of result rows written here */ 2878 int *pnColumn, /* Number of result columns written here */ 2879 char **pzErrmsg /* Error msg written here */ 2880); 2881SQLITE_API void sqlite3_free_table(char **result); 2882 2883/* 2884** CAPI3REF: Formatted String Printing Functions 2885** 2886** These routines are work-alikes of the "printf()" family of functions 2887** from the standard C library. 2888** These routines understand most of the common formatting options from 2889** the standard library printf() 2890** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). 2891** See the [built-in printf()] documentation for details. 2892** 2893** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2894** results into memory obtained from [sqlite3_malloc64()]. 2895** The strings returned by these two routines should be 2896** released by [sqlite3_free()]. ^Both routines return a 2897** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough 2898** memory to hold the resulting string. 2899** 2900** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2901** the standard C library. The result is written into the 2902** buffer supplied as the second parameter whose size is given by 2903** the first parameter. Note that the order of the 2904** first two parameters is reversed from snprintf().)^ This is an 2905** historical accident that cannot be fixed without breaking 2906** backwards compatibility. ^(Note also that sqlite3_snprintf() 2907** returns a pointer to its buffer instead of the number of 2908** characters actually written into the buffer.)^ We admit that 2909** the number of characters written would be a more useful return 2910** value but we cannot change the implementation of sqlite3_snprintf() 2911** now without breaking compatibility. 2912** 2913** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2914** guarantees that the buffer is always zero-terminated. ^The first 2915** parameter "n" is the total size of the buffer, including space for 2916** the zero terminator. So the longest string that can be completely 2917** written will be n-1 characters. 2918** 2919** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2920** 2921** See also: [built-in printf()], [printf() SQL function] 2922*/ 2923SQLITE_API char *sqlite3_mprintf(const char*,...); 2924SQLITE_API char *sqlite3_vmprintf(const char*, va_list); 2925SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 2926SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2927 2928/* 2929** CAPI3REF: Memory Allocation Subsystem 2930** 2931** The SQLite core uses these three routines for all of its own 2932** internal memory allocation needs. "Core" in the previous sentence 2933** does not include operating-system specific [VFS] implementation. The 2934** Windows VFS uses native malloc() and free() for some operations. 2935** 2936** ^The sqlite3_malloc() routine returns a pointer to a block 2937** of memory at least N bytes in length, where N is the parameter. 2938** ^If sqlite3_malloc() is unable to obtain sufficient free 2939** memory, it returns a NULL pointer. ^If the parameter N to 2940** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2941** a NULL pointer. 2942** 2943** ^The sqlite3_malloc64(N) routine works just like 2944** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2945** of a signed 32-bit integer. 2946** 2947** ^Calling sqlite3_free() with a pointer previously returned 2948** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2949** that it might be reused. ^The sqlite3_free() routine is 2950** a no-op if is called with a NULL pointer. Passing a NULL pointer 2951** to sqlite3_free() is harmless. After being freed, memory 2952** should neither be read nor written. Even reading previously freed 2953** memory might result in a segmentation fault or other severe error. 2954** Memory corruption, a segmentation fault, or other severe error 2955** might result if sqlite3_free() is called with a non-NULL pointer that 2956** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2957** 2958** ^The sqlite3_realloc(X,N) interface attempts to resize a 2959** prior memory allocation X to be at least N bytes. 2960** ^If the X parameter to sqlite3_realloc(X,N) 2961** is a NULL pointer then its behavior is identical to calling 2962** sqlite3_malloc(N). 2963** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2964** negative then the behavior is exactly the same as calling 2965** sqlite3_free(X). 2966** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2967** of at least N bytes in size or NULL if insufficient memory is available. 2968** ^If M is the size of the prior allocation, then min(N,M) bytes 2969** of the prior allocation are copied into the beginning of buffer returned 2970** by sqlite3_realloc(X,N) and the prior allocation is freed. 2971** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2972** prior allocation is not freed. 2973** 2974** ^The sqlite3_realloc64(X,N) interfaces works the same as 2975** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2976** of a 32-bit signed integer. 2977** 2978** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2979** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2980** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2981** ^The value returned by sqlite3_msize(X) might be larger than the number 2982** of bytes requested when X was allocated. ^If X is a NULL pointer then 2983** sqlite3_msize(X) returns zero. If X points to something that is not 2984** the beginning of memory allocation, or if it points to a formerly 2985** valid memory allocation that has now been freed, then the behavior 2986** of sqlite3_msize(X) is undefined and possibly harmful. 2987** 2988** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2989** sqlite3_malloc64(), and sqlite3_realloc64() 2990** is always aligned to at least an 8 byte boundary, or to a 2991** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2992** option is used. 2993** 2994** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2995** must be either NULL or else pointers obtained from a prior 2996** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2997** not yet been released. 2998** 2999** The application must not read or write any part of 3000** a block of memory after it has been released using 3001** [sqlite3_free()] or [sqlite3_realloc()]. 3002*/ 3003SQLITE_API void *sqlite3_malloc(int); 3004SQLITE_API void *sqlite3_malloc64(sqlite3_uint64); 3005SQLITE_API void *sqlite3_realloc(void*, int); 3006SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64); 3007SQLITE_API void sqlite3_free(void*); 3008SQLITE_API sqlite3_uint64 sqlite3_msize(void*); 3009 3010/* 3011** CAPI3REF: Memory Allocator Statistics 3012** 3013** SQLite provides these two interfaces for reporting on the status 3014** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 3015** routines, which form the built-in memory allocation subsystem. 3016** 3017** ^The [sqlite3_memory_used()] routine returns the number of bytes 3018** of memory currently outstanding (malloced but not freed). 3019** ^The [sqlite3_memory_highwater()] routine returns the maximum 3020** value of [sqlite3_memory_used()] since the high-water mark 3021** was last reset. ^The values returned by [sqlite3_memory_used()] and 3022** [sqlite3_memory_highwater()] include any overhead 3023** added by SQLite in its implementation of [sqlite3_malloc()], 3024** but not overhead added by the any underlying system library 3025** routines that [sqlite3_malloc()] may call. 3026** 3027** ^The memory high-water mark is reset to the current value of 3028** [sqlite3_memory_used()] if and only if the parameter to 3029** [sqlite3_memory_highwater()] is true. ^The value returned 3030** by [sqlite3_memory_highwater(1)] is the high-water mark 3031** prior to the reset. 3032*/ 3033SQLITE_API sqlite3_int64 sqlite3_memory_used(void); 3034SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 3035 3036/* 3037** CAPI3REF: Pseudo-Random Number Generator 3038** 3039** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 3040** select random [ROWID | ROWIDs] when inserting new records into a table that 3041** already uses the largest possible [ROWID]. The PRNG is also used for 3042** the built-in random() and randomblob() SQL functions. This interface allows 3043** applications to access the same PRNG for other purposes. 3044** 3045** ^A call to this routine stores N bytes of randomness into buffer P. 3046** ^The P parameter can be a NULL pointer. 3047** 3048** ^If this routine has not been previously called or if the previous 3049** call had N less than one or a NULL pointer for P, then the PRNG is 3050** seeded using randomness obtained from the xRandomness method of 3051** the default [sqlite3_vfs] object. 3052** ^If the previous call to this routine had an N of 1 or more and a 3053** non-NULL P then the pseudo-randomness is generated 3054** internally and without recourse to the [sqlite3_vfs] xRandomness 3055** method. 3056*/ 3057SQLITE_API void sqlite3_randomness(int N, void *P); 3058 3059/* 3060** CAPI3REF: Compile-Time Authorization Callbacks 3061** METHOD: sqlite3 3062** KEYWORDS: {authorizer callback} 3063** 3064** ^This routine registers an authorizer callback with a particular 3065** [database connection], supplied in the first argument. 3066** ^The authorizer callback is invoked as SQL statements are being compiled 3067** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 3068** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 3069** and [sqlite3_prepare16_v3()]. ^At various 3070** points during the compilation process, as logic is being created 3071** to perform various actions, the authorizer callback is invoked to 3072** see if those actions are allowed. ^The authorizer callback should 3073** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 3074** specific action but allow the SQL statement to continue to be 3075** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 3076** rejected with an error. ^If the authorizer callback returns 3077** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 3078** then the [sqlite3_prepare_v2()] or equivalent call that triggered 3079** the authorizer will fail with an error message. 3080** 3081** When the callback returns [SQLITE_OK], that means the operation 3082** requested is ok. ^When the callback returns [SQLITE_DENY], the 3083** [sqlite3_prepare_v2()] or equivalent call that triggered the 3084** authorizer will fail with an error message explaining that 3085** access is denied. 3086** 3087** ^The first parameter to the authorizer callback is a copy of the third 3088** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 3089** to the callback is an integer [SQLITE_COPY | action code] that specifies 3090** the particular action to be authorized. ^The third through sixth parameters 3091** to the callback are either NULL pointers or zero-terminated strings 3092** that contain additional details about the action to be authorized. 3093** Applications must always be prepared to encounter a NULL pointer in any 3094** of the third through the sixth parameters of the authorization callback. 3095** 3096** ^If the action code is [SQLITE_READ] 3097** and the callback returns [SQLITE_IGNORE] then the 3098** [prepared statement] statement is constructed to substitute 3099** a NULL value in place of the table column that would have 3100** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 3101** return can be used to deny an untrusted user access to individual 3102** columns of a table. 3103** ^When a table is referenced by a [SELECT] but no column values are 3104** extracted from that table (for example in a query like 3105** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 3106** is invoked once for that table with a column name that is an empty string. 3107** ^If the action code is [SQLITE_DELETE] and the callback returns 3108** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 3109** [truncate optimization] is disabled and all rows are deleted individually. 3110** 3111** An authorizer is used when [sqlite3_prepare | preparing] 3112** SQL statements from an untrusted source, to ensure that the SQL statements 3113** do not try to access data they are not allowed to see, or that they do not 3114** try to execute malicious statements that damage the database. For 3115** example, an application may allow a user to enter arbitrary 3116** SQL queries for evaluation by a database. But the application does 3117** not want the user to be able to make arbitrary changes to the 3118** database. An authorizer could then be put in place while the 3119** user-entered SQL is being [sqlite3_prepare | prepared] that 3120** disallows everything except [SELECT] statements. 3121** 3122** Applications that need to process SQL from untrusted sources 3123** might also consider lowering resource limits using [sqlite3_limit()] 3124** and limiting database size using the [max_page_count] [PRAGMA] 3125** in addition to using an authorizer. 3126** 3127** ^(Only a single authorizer can be in place on a database connection 3128** at a time. Each call to sqlite3_set_authorizer overrides the 3129** previous call.)^ ^Disable the authorizer by installing a NULL callback. 3130** The authorizer is disabled by default. 3131** 3132** The authorizer callback must not do anything that will modify 3133** the database connection that invoked the authorizer callback. 3134** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3135** database connections for the meaning of "modify" in this paragraph. 3136** 3137** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 3138** statement might be re-prepared during [sqlite3_step()] due to a 3139** schema change. Hence, the application should ensure that the 3140** correct authorizer callback remains in place during the [sqlite3_step()]. 3141** 3142** ^Note that the authorizer callback is invoked only during 3143** [sqlite3_prepare()] or its variants. Authorization is not 3144** performed during statement evaluation in [sqlite3_step()], unless 3145** as stated in the previous paragraph, sqlite3_step() invokes 3146** sqlite3_prepare_v2() to reprepare a statement after a schema change. 3147*/ 3148SQLITE_API int sqlite3_set_authorizer( 3149 sqlite3*, 3150 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 3151 void *pUserData 3152); 3153 3154#ifdef SQLITE_ENABLE_DROPTABLE_CALLBACK 3155SQLITE_API int sqlite3_set_droptable_handle( 3156 sqlite3 *db, 3157 void (*xFunc)(sqlite3*,const char*,const char*) 3158); 3159#endif 3160 3161/* 3162** CAPI3REF: Authorizer Return Codes 3163** 3164** The [sqlite3_set_authorizer | authorizer callback function] must 3165** return either [SQLITE_OK] or one of these two constants in order 3166** to signal SQLite whether or not the action is permitted. See the 3167** [sqlite3_set_authorizer | authorizer documentation] for additional 3168** information. 3169** 3170** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 3171** returned from the [sqlite3_vtab_on_conflict()] interface. 3172*/ 3173#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 3174#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 3175 3176/* 3177** CAPI3REF: Authorizer Action Codes 3178** 3179** The [sqlite3_set_authorizer()] interface registers a callback function 3180** that is invoked to authorize certain SQL statement actions. The 3181** second parameter to the callback is an integer code that specifies 3182** what action is being authorized. These are the integer action codes that 3183** the authorizer callback may be passed. 3184** 3185** These action code values signify what kind of operation is to be 3186** authorized. The 3rd and 4th parameters to the authorization 3187** callback function will be parameters or NULL depending on which of these 3188** codes is used as the second parameter. ^(The 5th parameter to the 3189** authorizer callback is the name of the database ("main", "temp", 3190** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 3191** is the name of the inner-most trigger or view that is responsible for 3192** the access attempt or NULL if this access attempt is directly from 3193** top-level SQL code. 3194*/ 3195/******************************************* 3rd ************ 4th ***********/ 3196#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 3197#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 3198#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 3199#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 3200#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 3201#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 3202#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 3203#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 3204#define SQLITE_DELETE 9 /* Table Name NULL */ 3205#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 3206#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 3207#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 3208#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 3209#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 3210#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 3211#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 3212#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 3213#define SQLITE_INSERT 18 /* Table Name NULL */ 3214#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 3215#define SQLITE_READ 20 /* Table Name Column Name */ 3216#define SQLITE_SELECT 21 /* NULL NULL */ 3217#define SQLITE_TRANSACTION 22 /* Operation NULL */ 3218#define SQLITE_UPDATE 23 /* Table Name Column Name */ 3219#define SQLITE_ATTACH 24 /* Filename NULL */ 3220#define SQLITE_DETACH 25 /* Database Name NULL */ 3221#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 3222#define SQLITE_REINDEX 27 /* Index Name NULL */ 3223#define SQLITE_ANALYZE 28 /* Table Name NULL */ 3224#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 3225#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 3226#define SQLITE_FUNCTION 31 /* NULL Function Name */ 3227#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 3228#define SQLITE_COPY 0 /* No longer used */ 3229#define SQLITE_RECURSIVE 33 /* NULL NULL */ 3230 3231/* 3232** CAPI3REF: Tracing And Profiling Functions 3233** METHOD: sqlite3 3234** 3235** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 3236** instead of the routines described here. 3237** 3238** These routines register callback functions that can be used for 3239** tracing and profiling the execution of SQL statements. 3240** 3241** ^The callback function registered by sqlite3_trace() is invoked at 3242** various times when an SQL statement is being run by [sqlite3_step()]. 3243** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 3244** SQL statement text as the statement first begins executing. 3245** ^(Additional sqlite3_trace() callbacks might occur 3246** as each triggered subprogram is entered. The callbacks for triggers 3247** contain a UTF-8 SQL comment that identifies the trigger.)^ 3248** 3249** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 3250** the length of [bound parameter] expansion in the output of sqlite3_trace(). 3251** 3252** ^The callback function registered by sqlite3_profile() is invoked 3253** as each SQL statement finishes. ^The profile callback contains 3254** the original statement text and an estimate of wall-clock time 3255** of how long that statement took to run. ^The profile callback 3256** time is in units of nanoseconds, however the current implementation 3257** is only capable of millisecond resolution so the six least significant 3258** digits in the time are meaningless. Future versions of SQLite 3259** might provide greater resolution on the profiler callback. Invoking 3260** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the 3261** profile callback. 3262*/ 3263SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 3264 void(*xTrace)(void*,const char*), void*); 3265SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 3266 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 3267 3268/* 3269** CAPI3REF: SQL Trace Event Codes 3270** KEYWORDS: SQLITE_TRACE 3271** 3272** These constants identify classes of events that can be monitored 3273** using the [sqlite3_trace_v2()] tracing logic. The M argument 3274** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of 3275** the following constants. ^The first argument to the trace callback 3276** is one of the following constants. 3277** 3278** New tracing constants may be added in future releases. 3279** 3280** ^A trace callback has four arguments: xCallback(T,C,P,X). 3281** ^The T argument is one of the integer type codes above. 3282** ^The C argument is a copy of the context pointer passed in as the 3283** fourth argument to [sqlite3_trace_v2()]. 3284** The P and X arguments are pointers whose meanings depend on T. 3285** 3286** <dl> 3287** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 3288** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 3289** first begins running and possibly at other times during the 3290** execution of the prepared statement, such as at the start of each 3291** trigger subprogram. ^The P argument is a pointer to the 3292** [prepared statement]. ^The X argument is a pointer to a string which 3293** is the unexpanded SQL text of the prepared statement or an SQL comment 3294** that indicates the invocation of a trigger. ^The callback can compute 3295** the same text that would have been returned by the legacy [sqlite3_trace()] 3296** interface by using the X argument when X begins with "--" and invoking 3297** [sqlite3_expanded_sql(P)] otherwise. 3298** 3299** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 3300** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 3301** information as is provided by the [sqlite3_profile()] callback. 3302** ^The P argument is a pointer to the [prepared statement] and the 3303** X argument points to a 64-bit integer which is the estimated of 3304** the number of nanosecond that the prepared statement took to run. 3305** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 3306** 3307** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 3308** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 3309** statement generates a single row of result. 3310** ^The P argument is a pointer to the [prepared statement] and the 3311** X argument is unused. 3312** 3313** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 3314** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 3315** connection closes. 3316** ^The P argument is a pointer to the [database connection] object 3317** and the X argument is unused. 3318** </dl> 3319*/ 3320#define SQLITE_TRACE_STMT 0x01 3321#define SQLITE_TRACE_PROFILE 0x02 3322#define SQLITE_TRACE_ROW 0x04 3323#define SQLITE_TRACE_CLOSE 0x08 3324 3325/* 3326** CAPI3REF: SQL Trace Hook 3327** METHOD: sqlite3 3328** 3329** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 3330** function X against [database connection] D, using property mask M 3331** and context pointer P. ^If the X callback is 3332** NULL or if the M mask is zero, then tracing is disabled. The 3333** M argument should be the bitwise OR-ed combination of 3334** zero or more [SQLITE_TRACE] constants. 3335** 3336** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 3337** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 3338** 3339** ^The X callback is invoked whenever any of the events identified by 3340** mask M occur. ^The integer return value from the callback is currently 3341** ignored, though this may change in future releases. Callback 3342** implementations should return zero to ensure future compatibility. 3343** 3344** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 3345** ^The T argument is one of the [SQLITE_TRACE] 3346** constants to indicate why the callback was invoked. 3347** ^The C argument is a copy of the context pointer. 3348** The P and X arguments are pointers whose meanings depend on T. 3349** 3350** The sqlite3_trace_v2() interface is intended to replace the legacy 3351** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 3352** are deprecated. 3353*/ 3354SQLITE_API int sqlite3_trace_v2( 3355 sqlite3*, 3356 unsigned uMask, 3357 int(*xCallback)(unsigned,void*,void*,void*), 3358 void *pCtx 3359); 3360 3361/* 3362** CAPI3REF: Query Progress Callbacks 3363** METHOD: sqlite3 3364** 3365** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 3366** function X to be invoked periodically during long running calls to 3367** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 3368** database connection D. An example use for this 3369** interface is to keep a GUI updated during a large query. 3370** 3371** ^The parameter P is passed through as the only parameter to the 3372** callback function X. ^The parameter N is the approximate number of 3373** [virtual machine instructions] that are evaluated between successive 3374** invocations of the callback X. ^If N is less than one then the progress 3375** handler is disabled. 3376** 3377** ^Only a single progress handler may be defined at one time per 3378** [database connection]; setting a new progress handler cancels the 3379** old one. ^Setting parameter X to NULL disables the progress handler. 3380** ^The progress handler is also disabled by setting N to a value less 3381** than 1. 3382** 3383** ^If the progress callback returns non-zero, the operation is 3384** interrupted. This feature can be used to implement a 3385** "Cancel" button on a GUI progress dialog box. 3386** 3387** The progress handler callback must not do anything that will modify 3388** the database connection that invoked the progress handler. 3389** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3390** database connections for the meaning of "modify" in this paragraph. 3391** 3392*/ 3393SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3394 3395/* 3396** CAPI3REF: Opening A New Database Connection 3397** CONSTRUCTOR: sqlite3 3398** 3399** ^These routines open an SQLite database file as specified by the 3400** filename argument. ^The filename argument is interpreted as UTF-8 for 3401** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3402** order for sqlite3_open16(). ^(A [database connection] handle is usually 3403** returned in *ppDb, even if an error occurs. The only exception is that 3404** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3405** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3406** object.)^ ^(If the database is opened (and/or created) successfully, then 3407** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3408** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3409** an English language description of the error following a failure of any 3410** of the sqlite3_open() routines. 3411** 3412** ^The default encoding will be UTF-8 for databases created using 3413** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3414** created using sqlite3_open16() will be UTF-16 in the native byte order. 3415** 3416** Whether or not an error occurs when it is opened, resources 3417** associated with the [database connection] handle should be released by 3418** passing it to [sqlite3_close()] when it is no longer required. 3419** 3420** The sqlite3_open_v2() interface works like sqlite3_open() 3421** except that it accepts two additional parameters for additional control 3422** over the new database connection. ^(The flags parameter to 3423** sqlite3_open_v2() must include, at a minimum, one of the following 3424** three flag combinations:)^ 3425** 3426** <dl> 3427** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3428** <dd>The database is opened in read-only mode. If the database does not 3429** already exist, an error is returned.</dd>)^ 3430** 3431** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3432** <dd>The database is opened for reading and writing if possible, or reading 3433** only if the file is write protected by the operating system. In either 3434** case the database must already exist, otherwise an error is returned.</dd>)^ 3435** 3436** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3437** <dd>The database is opened for reading and writing, and is created if 3438** it does not already exist. This is the behavior that is always used for 3439** sqlite3_open() and sqlite3_open16().</dd>)^ 3440** </dl> 3441** 3442** In addition to the required flags, the following optional flags are 3443** also supported: 3444** 3445** <dl> 3446** ^(<dt>[SQLITE_OPEN_URI]</dt> 3447** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^ 3448** 3449** ^(<dt>[SQLITE_OPEN_MEMORY]</dt> 3450** <dd>The database will be opened as an in-memory database. The database 3451** is named by the "filename" argument for the purposes of cache-sharing, 3452** if shared cache mode is enabled, but the "filename" is otherwise ignored. 3453** </dd>)^ 3454** 3455** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt> 3456** <dd>The new database connection will use the "multi-thread" 3457** [threading mode].)^ This means that separate threads are allowed 3458** to use SQLite at the same time, as long as each thread is using 3459** a different [database connection]. 3460** 3461** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt> 3462** <dd>The new database connection will use the "serialized" 3463** [threading mode].)^ This means the multiple threads can safely 3464** attempt to use the same database connection at the same time. 3465** (Mutexes will block any actual concurrency, but in this mode 3466** there is no harm in trying.) 3467** 3468** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt> 3469** <dd>The database is opened [shared cache] enabled, overriding 3470** the default shared cache setting provided by 3471** [sqlite3_enable_shared_cache()].)^ 3472** The [use of shared cache mode is discouraged] and hence shared cache 3473** capabilities may be omitted from many builds of SQLite. In such cases, 3474** this option is a no-op. 3475** 3476** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt> 3477** <dd>The database is opened [shared cache] disabled, overriding 3478** the default shared cache setting provided by 3479** [sqlite3_enable_shared_cache()].)^ 3480** 3481** [[OPEN_EXRESCODE]] ^(<dt>[SQLITE_OPEN_EXRESCODE]</dt> 3482** <dd>The database connection comes up in "extended result code mode". 3483** In other words, the database behaves has if 3484** [sqlite3_extended_result_codes(db,1)] where called on the database 3485** connection as soon as the connection is created. In addition to setting 3486** the extended result code mode, this flag also causes [sqlite3_open_v2()] 3487** to return an extended result code.</dd> 3488** 3489** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt> 3490** <dd>The database filename is not allowed to contain a symbolic link</dd> 3491** </dl>)^ 3492** 3493** If the 3rd parameter to sqlite3_open_v2() is not one of the 3494** required combinations shown above optionally combined with other 3495** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3496** then the behavior is undefined. Historic versions of SQLite 3497** have silently ignored surplus bits in the flags parameter to 3498** sqlite3_open_v2(), however that behavior might not be carried through 3499** into future versions of SQLite and so applications should not rely 3500** upon it. Note in particular that the SQLITE_OPEN_EXCLUSIVE flag is a no-op 3501** for sqlite3_open_v2(). The SQLITE_OPEN_EXCLUSIVE does *not* cause 3502** the open to fail if the database already exists. The SQLITE_OPEN_EXCLUSIVE 3503** flag is intended for use by the [sqlite3_vfs|VFS interface] only, and not 3504** by sqlite3_open_v2(). 3505** 3506** ^The fourth parameter to sqlite3_open_v2() is the name of the 3507** [sqlite3_vfs] object that defines the operating system interface that 3508** the new database connection should use. ^If the fourth parameter is 3509** a NULL pointer then the default [sqlite3_vfs] object is used. 3510** 3511** ^If the filename is ":memory:", then a private, temporary in-memory database 3512** is created for the connection. ^This in-memory database will vanish when 3513** the database connection is closed. Future versions of SQLite might 3514** make use of additional special filenames that begin with the ":" character. 3515** It is recommended that when a database filename actually does begin with 3516** a ":" character you should prefix the filename with a pathname such as 3517** "./" to avoid ambiguity. 3518** 3519** ^If the filename is an empty string, then a private, temporary 3520** on-disk database will be created. ^This private database will be 3521** automatically deleted as soon as the database connection is closed. 3522** 3523** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3524** 3525** ^If [URI filename] interpretation is enabled, and the filename argument 3526** begins with "file:", then the filename is interpreted as a URI. ^URI 3527** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3528** set in the third argument to sqlite3_open_v2(), or if it has 3529** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3530** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3531** URI filename interpretation is turned off 3532** by default, but future releases of SQLite might enable URI filename 3533** interpretation by default. See "[URI filenames]" for additional 3534** information. 3535** 3536** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3537** authority, then it must be either an empty string or the string 3538** "localhost". ^If the authority is not an empty string or "localhost", an 3539** error is returned to the caller. ^The fragment component of a URI, if 3540** present, is ignored. 3541** 3542** ^SQLite uses the path component of the URI as the name of the disk file 3543** which contains the database. ^If the path begins with a '/' character, 3544** then it is interpreted as an absolute path. ^If the path does not begin 3545** with a '/' (meaning that the authority section is omitted from the URI) 3546** then the path is interpreted as a relative path. 3547** ^(On windows, the first component of an absolute path 3548** is a drive specification (e.g. "C:").)^ 3549** 3550** [[core URI query parameters]] 3551** The query component of a URI may contain parameters that are interpreted 3552** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3553** SQLite and its built-in [VFSes] interpret the 3554** following query parameters: 3555** 3556** <ul> 3557** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3558** a VFS object that provides the operating system interface that should 3559** be used to access the database file on disk. ^If this option is set to 3560** an empty string the default VFS object is used. ^Specifying an unknown 3561** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3562** present, then the VFS specified by the option takes precedence over 3563** the value passed as the fourth parameter to sqlite3_open_v2(). 3564** 3565** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3566** "rwc", or "memory". Attempting to set it to any other value is 3567** an error)^. 3568** ^If "ro" is specified, then the database is opened for read-only 3569** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3570** third argument to sqlite3_open_v2(). ^If the mode option is set to 3571** "rw", then the database is opened for read-write (but not create) 3572** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3573** been set. ^Value "rwc" is equivalent to setting both 3574** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3575** set to "memory" then a pure [in-memory database] that never reads 3576** or writes from disk is used. ^It is an error to specify a value for 3577** the mode parameter that is less restrictive than that specified by 3578** the flags passed in the third parameter to sqlite3_open_v2(). 3579** 3580** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3581** "private". ^Setting it to "shared" is equivalent to setting the 3582** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3583** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3584** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3585** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3586** a URI filename, its value overrides any behavior requested by setting 3587** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3588** 3589** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3590** [powersafe overwrite] property does or does not apply to the 3591** storage media on which the database file resides. 3592** 3593** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3594** which if set disables file locking in rollback journal modes. This 3595** is useful for accessing a database on a filesystem that does not 3596** support locking. Caution: Database corruption might result if two 3597** or more processes write to the same database and any one of those 3598** processes uses nolock=1. 3599** 3600** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3601** parameter that indicates that the database file is stored on 3602** read-only media. ^When immutable is set, SQLite assumes that the 3603** database file cannot be changed, even by a process with higher 3604** privilege, and so the database is opened read-only and all locking 3605** and change detection is disabled. Caution: Setting the immutable 3606** property on a database file that does in fact change can result 3607** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3608** See also: [SQLITE_IOCAP_IMMUTABLE]. 3609** 3610** </ul> 3611** 3612** ^Specifying an unknown parameter in the query component of a URI is not an 3613** error. Future versions of SQLite might understand additional query 3614** parameters. See "[query parameters with special meaning to SQLite]" for 3615** additional information. 3616** 3617** [[URI filename examples]] <h3>URI filename examples</h3> 3618** 3619** <table border="1" align=center cellpadding=5> 3620** <tr><th> URI filenames <th> Results 3621** <tr><td> file:data.db <td> 3622** Open the file "data.db" in the current directory. 3623** <tr><td> file:/home/fred/data.db<br> 3624** file:///home/fred/data.db <br> 3625** file://localhost/home/fred/data.db <br> <td> 3626** Open the database file "/home/fred/data.db". 3627** <tr><td> file://darkstar/home/fred/data.db <td> 3628** An error. "darkstar" is not a recognized authority. 3629** <tr><td style="white-space:nowrap"> 3630** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3631** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3632** C:. Note that the %20 escaping in this example is not strictly 3633** necessary - space characters can be used literally 3634** in URI filenames. 3635** <tr><td> file:data.db?mode=ro&cache=private <td> 3636** Open file "data.db" in the current directory for read-only access. 3637** Regardless of whether or not shared-cache mode is enabled by 3638** default, use a private cache. 3639** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3640** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3641** that uses dot-files in place of posix advisory locking. 3642** <tr><td> file:data.db?mode=readonly <td> 3643** An error. "readonly" is not a valid option for the "mode" parameter. 3644** Use "ro" instead: "file:data.db?mode=ro". 3645** </table> 3646** 3647** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3648** query components of a URI. A hexadecimal escape sequence consists of a 3649** percent sign - "%" - followed by exactly two hexadecimal digits 3650** specifying an octet value. ^Before the path or query components of a 3651** URI filename are interpreted, they are encoded using UTF-8 and all 3652** hexadecimal escape sequences replaced by a single byte containing the 3653** corresponding octet. If this process generates an invalid UTF-8 encoding, 3654** the results are undefined. 3655** 3656** <b>Note to Windows users:</b> The encoding used for the filename argument 3657** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3658** codepage is currently defined. Filenames containing international 3659** characters must be converted to UTF-8 prior to passing them into 3660** sqlite3_open() or sqlite3_open_v2(). 3661** 3662** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3663** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3664** features that require the use of temporary files may fail. 3665** 3666** See also: [sqlite3_temp_directory] 3667*/ 3668SQLITE_API int sqlite3_open( 3669 const char *filename, /* Database filename (UTF-8) */ 3670 sqlite3 **ppDb /* OUT: SQLite db handle */ 3671); 3672SQLITE_API int sqlite3_open16( 3673 const void *filename, /* Database filename (UTF-16) */ 3674 sqlite3 **ppDb /* OUT: SQLite db handle */ 3675); 3676SQLITE_API int sqlite3_open_v2( 3677 const char *filename, /* Database filename (UTF-8) */ 3678 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3679 int flags, /* Flags */ 3680 const char *zVfs /* Name of VFS module to use */ 3681); 3682 3683/* 3684** CAPI3REF: Obtain Values For URI Parameters 3685** 3686** These are utility routines, useful to [VFS|custom VFS implementations], 3687** that check if a database file was a URI that contained a specific query 3688** parameter, and if so obtains the value of that query parameter. 3689** 3690** The first parameter to these interfaces (hereafter referred to 3691** as F) must be one of: 3692** <ul> 3693** <li> A database filename pointer created by the SQLite core and 3694** passed into the xOpen() method of a VFS implemention, or 3695** <li> A filename obtained from [sqlite3_db_filename()], or 3696** <li> A new filename constructed using [sqlite3_create_filename()]. 3697** </ul> 3698** If the F parameter is not one of the above, then the behavior is 3699** undefined and probably undesirable. Older versions of SQLite were 3700** more tolerant of invalid F parameters than newer versions. 3701** 3702** If F is a suitable filename (as described in the previous paragraph) 3703** and if P is the name of the query parameter, then 3704** sqlite3_uri_parameter(F,P) returns the value of the P 3705** parameter if it exists or a NULL pointer if P does not appear as a 3706** query parameter on F. If P is a query parameter of F and it 3707** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3708** a pointer to an empty string. 3709** 3710** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3711** parameter and returns true (1) or false (0) according to the value 3712** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3713** value of query parameter P is one of "yes", "true", or "on" in any 3714** case or if the value begins with a non-zero number. The 3715** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3716** query parameter P is one of "no", "false", or "off" in any case or 3717** if the value begins with a numeric zero. If P is not a query 3718** parameter on F or if the value of P does not match any of the 3719** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3720** 3721** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3722** 64-bit signed integer and returns that integer, or D if P does not 3723** exist. If the value of P is something other than an integer, then 3724** zero is returned. 3725** 3726** The sqlite3_uri_key(F,N) returns a pointer to the name (not 3727** the value) of the N-th query parameter for filename F, or a NULL 3728** pointer if N is less than zero or greater than the number of query 3729** parameters minus 1. The N value is zero-based so N should be 0 to obtain 3730** the name of the first query parameter, 1 for the second parameter, and 3731** so forth. 3732** 3733** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3734** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3735** is not a database file pathname pointer that the SQLite core passed 3736** into the xOpen VFS method, then the behavior of this routine is undefined 3737** and probably undesirable. 3738** 3739** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F 3740** parameter can also be the name of a rollback journal file or WAL file 3741** in addition to the main database file. Prior to version 3.31.0, these 3742** routines would only work if F was the name of the main database file. 3743** When the F parameter is the name of the rollback journal or WAL file, 3744** it has access to all the same query parameters as were found on the 3745** main database file. 3746** 3747** See the [URI filename] documentation for additional information. 3748*/ 3749SQLITE_API const char *sqlite3_uri_parameter(sqlite3_filename z, const char *zParam); 3750SQLITE_API int sqlite3_uri_boolean(sqlite3_filename z, const char *zParam, int bDefault); 3751SQLITE_API sqlite3_int64 sqlite3_uri_int64(sqlite3_filename, const char*, sqlite3_int64); 3752SQLITE_API const char *sqlite3_uri_key(sqlite3_filename z, int N); 3753 3754/* 3755** CAPI3REF: Translate filenames 3756** 3757** These routines are available to [VFS|custom VFS implementations] for 3758** translating filenames between the main database file, the journal file, 3759** and the WAL file. 3760** 3761** If F is the name of an sqlite database file, journal file, or WAL file 3762** passed by the SQLite core into the VFS, then sqlite3_filename_database(F) 3763** returns the name of the corresponding database file. 3764** 3765** If F is the name of an sqlite database file, journal file, or WAL file 3766** passed by the SQLite core into the VFS, or if F is a database filename 3767** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F) 3768** returns the name of the corresponding rollback journal file. 3769** 3770** If F is the name of an sqlite database file, journal file, or WAL file 3771** that was passed by the SQLite core into the VFS, or if F is a database 3772** filename obtained from [sqlite3_db_filename()], then 3773** sqlite3_filename_wal(F) returns the name of the corresponding 3774** WAL file. 3775** 3776** In all of the above, if F is not the name of a database, journal or WAL 3777** filename passed into the VFS from the SQLite core and F is not the 3778** return value from [sqlite3_db_filename()], then the result is 3779** undefined and is likely a memory access violation. 3780*/ 3781SQLITE_API const char *sqlite3_filename_database(sqlite3_filename); 3782SQLITE_API const char *sqlite3_filename_journal(sqlite3_filename); 3783SQLITE_API const char *sqlite3_filename_wal(sqlite3_filename); 3784 3785/* 3786** CAPI3REF: Database File Corresponding To A Journal 3787** 3788** ^If X is the name of a rollback or WAL-mode journal file that is 3789** passed into the xOpen method of [sqlite3_vfs], then 3790** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file] 3791** object that represents the main database file. 3792** 3793** This routine is intended for use in custom [VFS] implementations 3794** only. It is not a general-purpose interface. 3795** The argument sqlite3_file_object(X) must be a filename pointer that 3796** has been passed into [sqlite3_vfs].xOpen method where the 3797** flags parameter to xOpen contains one of the bits 3798** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use 3799** of this routine results in undefined and probably undesirable 3800** behavior. 3801*/ 3802SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*); 3803 3804/* 3805** CAPI3REF: Create and Destroy VFS Filenames 3806** 3807** These interfces are provided for use by [VFS shim] implementations and 3808** are not useful outside of that context. 3809** 3810** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of 3811** database filename D with corresponding journal file J and WAL file W and 3812** with N URI parameters key/values pairs in the array P. The result from 3813** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that 3814** is safe to pass to routines like: 3815** <ul> 3816** <li> [sqlite3_uri_parameter()], 3817** <li> [sqlite3_uri_boolean()], 3818** <li> [sqlite3_uri_int64()], 3819** <li> [sqlite3_uri_key()], 3820** <li> [sqlite3_filename_database()], 3821** <li> [sqlite3_filename_journal()], or 3822** <li> [sqlite3_filename_wal()]. 3823** </ul> 3824** If a memory allocation error occurs, sqlite3_create_filename() might 3825** return a NULL pointer. The memory obtained from sqlite3_create_filename(X) 3826** must be released by a corresponding call to sqlite3_free_filename(Y). 3827** 3828** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array 3829** of 2*N pointers to strings. Each pair of pointers in this array corresponds 3830** to a key and value for a query parameter. The P parameter may be a NULL 3831** pointer if N is zero. None of the 2*N pointers in the P array may be 3832** NULL pointers and key pointers should not be empty strings. 3833** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may 3834** be NULL pointers, though they can be empty strings. 3835** 3836** The sqlite3_free_filename(Y) routine releases a memory allocation 3837** previously obtained from sqlite3_create_filename(). Invoking 3838** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op. 3839** 3840** If the Y parameter to sqlite3_free_filename(Y) is anything other 3841** than a NULL pointer or a pointer previously acquired from 3842** sqlite3_create_filename(), then bad things such as heap 3843** corruption or segfaults may occur. The value Y should not be 3844** used again after sqlite3_free_filename(Y) has been called. This means 3845** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y, 3846** then the corresponding [sqlite3_module.xClose() method should also be 3847** invoked prior to calling sqlite3_free_filename(Y). 3848*/ 3849SQLITE_API sqlite3_filename sqlite3_create_filename( 3850 const char *zDatabase, 3851 const char *zJournal, 3852 const char *zWal, 3853 int nParam, 3854 const char **azParam 3855); 3856SQLITE_API void sqlite3_free_filename(sqlite3_filename); 3857 3858/* 3859** CAPI3REF: Error Codes And Messages 3860** METHOD: sqlite3 3861** 3862** ^If the most recent sqlite3_* API call associated with 3863** [database connection] D failed, then the sqlite3_errcode(D) interface 3864** returns the numeric [result code] or [extended result code] for that 3865** API call. 3866** ^The sqlite3_extended_errcode() 3867** interface is the same except that it always returns the 3868** [extended result code] even when extended result codes are 3869** disabled. 3870** 3871** The values returned by sqlite3_errcode() and/or 3872** sqlite3_extended_errcode() might change with each API call. 3873** Except, there are some interfaces that are guaranteed to never 3874** change the value of the error code. The error-code preserving 3875** interfaces include the following: 3876** 3877** <ul> 3878** <li> sqlite3_errcode() 3879** <li> sqlite3_extended_errcode() 3880** <li> sqlite3_errmsg() 3881** <li> sqlite3_errmsg16() 3882** <li> sqlite3_error_offset() 3883** </ul> 3884** 3885** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3886** text that describes the error, as either UTF-8 or UTF-16 respectively. 3887** ^(Memory to hold the error message string is managed internally. 3888** The application does not need to worry about freeing the result. 3889** However, the error string might be overwritten or deallocated by 3890** subsequent calls to other SQLite interface functions.)^ 3891** 3892** ^The sqlite3_errstr() interface returns the English-language text 3893** that describes the [result code], as UTF-8. 3894** ^(Memory to hold the error message string is managed internally 3895** and must not be freed by the application)^. 3896** 3897** ^If the most recent error references a specific token in the input 3898** SQL, the sqlite3_error_offset() interface returns the byte offset 3899** of the start of that token. ^The byte offset returned by 3900** sqlite3_error_offset() assumes that the input SQL is UTF8. 3901** ^If the most recent error does not reference a specific token in the input 3902** SQL, then the sqlite3_error_offset() function returns -1. 3903** 3904** When the serialized [threading mode] is in use, it might be the 3905** case that a second error occurs on a separate thread in between 3906** the time of the first error and the call to these interfaces. 3907** When that happens, the second error will be reported since these 3908** interfaces always report the most recent result. To avoid 3909** this, each thread can obtain exclusive use of the [database connection] D 3910** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3911** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3912** all calls to the interfaces listed here are completed. 3913** 3914** If an interface fails with SQLITE_MISUSE, that means the interface 3915** was invoked incorrectly by the application. In that case, the 3916** error code and message may or may not be set. 3917*/ 3918SQLITE_API int sqlite3_errcode(sqlite3 *db); 3919SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 3920SQLITE_API const char *sqlite3_errmsg(sqlite3*); 3921SQLITE_API const void *sqlite3_errmsg16(sqlite3*); 3922SQLITE_API const char *sqlite3_errstr(int); 3923SQLITE_API int sqlite3_error_offset(sqlite3 *db); 3924 3925/* 3926** CAPI3REF: Prepared Statement Object 3927** KEYWORDS: {prepared statement} {prepared statements} 3928** 3929** An instance of this object represents a single SQL statement that 3930** has been compiled into binary form and is ready to be evaluated. 3931** 3932** Think of each SQL statement as a separate computer program. The 3933** original SQL text is source code. A prepared statement object 3934** is the compiled object code. All SQL must be converted into a 3935** prepared statement before it can be run. 3936** 3937** The life-cycle of a prepared statement object usually goes like this: 3938** 3939** <ol> 3940** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3941** <li> Bind values to [parameters] using the sqlite3_bind_*() 3942** interfaces. 3943** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3944** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3945** to step 2. Do this zero or more times. 3946** <li> Destroy the object using [sqlite3_finalize()]. 3947** </ol> 3948*/ 3949typedef struct sqlite3_stmt sqlite3_stmt; 3950 3951/* 3952** CAPI3REF: Run-time Limits 3953** METHOD: sqlite3 3954** 3955** ^(This interface allows the size of various constructs to be limited 3956** on a connection by connection basis. The first parameter is the 3957** [database connection] whose limit is to be set or queried. The 3958** second parameter is one of the [limit categories] that define a 3959** class of constructs to be size limited. The third parameter is the 3960** new limit for that construct.)^ 3961** 3962** ^If the new limit is a negative number, the limit is unchanged. 3963** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3964** [limits | hard upper bound] 3965** set at compile-time by a C preprocessor macro called 3966** [limits | SQLITE_MAX_<i>NAME</i>]. 3967** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3968** ^Attempts to increase a limit above its hard upper bound are 3969** silently truncated to the hard upper bound. 3970** 3971** ^Regardless of whether or not the limit was changed, the 3972** [sqlite3_limit()] interface returns the prior value of the limit. 3973** ^Hence, to find the current value of a limit without changing it, 3974** simply invoke this interface with the third parameter set to -1. 3975** 3976** Run-time limits are intended for use in applications that manage 3977** both their own internal database and also databases that are controlled 3978** by untrusted external sources. An example application might be a 3979** web browser that has its own databases for storing history and 3980** separate databases controlled by JavaScript applications downloaded 3981** off the Internet. The internal databases can be given the 3982** large, default limits. Databases managed by external sources can 3983** be given much smaller limits designed to prevent a denial of service 3984** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3985** interface to further control untrusted SQL. The size of the database 3986** created by an untrusted script can be contained using the 3987** [max_page_count] [PRAGMA]. 3988** 3989** New run-time limit categories may be added in future releases. 3990*/ 3991SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 3992 3993/* 3994** CAPI3REF: Run-Time Limit Categories 3995** KEYWORDS: {limit category} {*limit categories} 3996** 3997** These constants define various performance limits 3998** that can be lowered at run-time using [sqlite3_limit()]. 3999** The synopsis of the meanings of the various limits is shown below. 4000** Additional information is available at [limits | Limits in SQLite]. 4001** 4002** <dl> 4003** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 4004** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 4005** 4006** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 4007** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 4008** 4009** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 4010** <dd>The maximum number of columns in a table definition or in the 4011** result set of a [SELECT] or the maximum number of columns in an index 4012** or in an ORDER BY or GROUP BY clause.</dd>)^ 4013** 4014** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 4015** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 4016** 4017** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 4018** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 4019** 4020** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 4021** <dd>The maximum number of instructions in a virtual machine program 4022** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 4023** the equivalent tries to allocate space for more than this many opcodes 4024** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 4025** 4026** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 4027** <dd>The maximum number of arguments on a function.</dd>)^ 4028** 4029** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 4030** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 4031** 4032** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 4033** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 4034** <dd>The maximum length of the pattern argument to the [LIKE] or 4035** [GLOB] operators.</dd>)^ 4036** 4037** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 4038** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 4039** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 4040** 4041** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 4042** <dd>The maximum depth of recursion for triggers.</dd>)^ 4043** 4044** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 4045** <dd>The maximum number of auxiliary worker threads that a single 4046** [prepared statement] may start.</dd>)^ 4047** </dl> 4048*/ 4049#define SQLITE_LIMIT_LENGTH 0 4050#define SQLITE_LIMIT_SQL_LENGTH 1 4051#define SQLITE_LIMIT_COLUMN 2 4052#define SQLITE_LIMIT_EXPR_DEPTH 3 4053#define SQLITE_LIMIT_COMPOUND_SELECT 4 4054#define SQLITE_LIMIT_VDBE_OP 5 4055#define SQLITE_LIMIT_FUNCTION_ARG 6 4056#define SQLITE_LIMIT_ATTACHED 7 4057#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 4058#define SQLITE_LIMIT_VARIABLE_NUMBER 9 4059#define SQLITE_LIMIT_TRIGGER_DEPTH 10 4060#define SQLITE_LIMIT_WORKER_THREADS 11 4061 4062/* 4063** CAPI3REF: Prepare Flags 4064** 4065** These constants define various flags that can be passed into 4066** "prepFlags" parameter of the [sqlite3_prepare_v3()] and 4067** [sqlite3_prepare16_v3()] interfaces. 4068** 4069** New flags may be added in future releases of SQLite. 4070** 4071** <dl> 4072** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> 4073** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner 4074** that the prepared statement will be retained for a long time and 4075** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] 4076** and [sqlite3_prepare16_v3()] assume that the prepared statement will 4077** be used just once or at most a few times and then destroyed using 4078** [sqlite3_finalize()] relatively soon. The current implementation acts 4079** on this hint by avoiding the use of [lookaside memory] so as not to 4080** deplete the limited store of lookaside memory. Future versions of 4081** SQLite may act on this hint differently. 4082** 4083** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt> 4084** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used 4085** to be required for any prepared statement that wanted to use the 4086** [sqlite3_normalized_sql()] interface. However, the 4087** [sqlite3_normalized_sql()] interface is now available to all 4088** prepared statements, regardless of whether or not they use this 4089** flag. 4090** 4091** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt> 4092** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler 4093** to return an error (error code SQLITE_ERROR) if the statement uses 4094** any virtual tables. 4095** </dl> 4096*/ 4097#define SQLITE_PREPARE_PERSISTENT 0x01 4098#define SQLITE_PREPARE_NORMALIZE 0x02 4099#define SQLITE_PREPARE_NO_VTAB 0x04 4100 4101/* 4102** CAPI3REF: Compiling An SQL Statement 4103** KEYWORDS: {SQL statement compiler} 4104** METHOD: sqlite3 4105** CONSTRUCTOR: sqlite3_stmt 4106** 4107** To execute an SQL statement, it must first be compiled into a byte-code 4108** program using one of these routines. Or, in other words, these routines 4109** are constructors for the [prepared statement] object. 4110** 4111** The preferred routine to use is [sqlite3_prepare_v2()]. The 4112** [sqlite3_prepare()] interface is legacy and should be avoided. 4113** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used 4114** for special purposes. 4115** 4116** The use of the UTF-8 interfaces is preferred, as SQLite currently 4117** does all parsing using UTF-8. The UTF-16 interfaces are provided 4118** as a convenience. The UTF-16 interfaces work by converting the 4119** input text into UTF-8, then invoking the corresponding UTF-8 interface. 4120** 4121** The first argument, "db", is a [database connection] obtained from a 4122** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 4123** [sqlite3_open16()]. The database connection must not have been closed. 4124** 4125** The second argument, "zSql", is the statement to be compiled, encoded 4126** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), 4127** and sqlite3_prepare_v3() 4128** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), 4129** and sqlite3_prepare16_v3() use UTF-16. 4130** 4131** ^If the nByte argument is negative, then zSql is read up to the 4132** first zero terminator. ^If nByte is positive, then it is the 4133** number of bytes read from zSql. ^If nByte is zero, then no prepared 4134** statement is generated. 4135** If the caller knows that the supplied string is nul-terminated, then 4136** there is a small performance advantage to passing an nByte parameter that 4137** is the number of bytes in the input string <i>including</i> 4138** the nul-terminator. 4139** 4140** ^If pzTail is not NULL then *pzTail is made to point to the first byte 4141** past the end of the first SQL statement in zSql. These routines only 4142** compile the first statement in zSql, so *pzTail is left pointing to 4143** what remains uncompiled. 4144** 4145** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 4146** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 4147** to NULL. ^If the input text contains no SQL (if the input is an empty 4148** string or a comment) then *ppStmt is set to NULL. 4149** The calling procedure is responsible for deleting the compiled 4150** SQL statement using [sqlite3_finalize()] after it has finished with it. 4151** ppStmt may not be NULL. 4152** 4153** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 4154** otherwise an [error code] is returned. 4155** 4156** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), 4157** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. 4158** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) 4159** are retained for backwards compatibility, but their use is discouraged. 4160** ^In the "vX" interfaces, the prepared statement 4161** that is returned (the [sqlite3_stmt] object) contains a copy of the 4162** original SQL text. This causes the [sqlite3_step()] interface to 4163** behave differently in three ways: 4164** 4165** <ol> 4166** <li> 4167** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 4168** always used to do, [sqlite3_step()] will automatically recompile the SQL 4169** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 4170** retries will occur before sqlite3_step() gives up and returns an error. 4171** </li> 4172** 4173** <li> 4174** ^When an error occurs, [sqlite3_step()] will return one of the detailed 4175** [error codes] or [extended error codes]. ^The legacy behavior was that 4176** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 4177** and the application would have to make a second call to [sqlite3_reset()] 4178** in order to find the underlying cause of the problem. With the "v2" prepare 4179** interfaces, the underlying reason for the error is returned immediately. 4180** </li> 4181** 4182** <li> 4183** ^If the specific value bound to a [parameter | host parameter] in the 4184** WHERE clause might influence the choice of query plan for a statement, 4185** then the statement will be automatically recompiled, as if there had been 4186** a schema change, on the first [sqlite3_step()] call following any change 4187** to the [sqlite3_bind_text | bindings] of that [parameter]. 4188** ^The specific value of a WHERE-clause [parameter] might influence the 4189** choice of query plan if the parameter is the left-hand side of a [LIKE] 4190** or [GLOB] operator or if the parameter is compared to an indexed column 4191** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled. 4192** </li> 4193** </ol> 4194** 4195** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having 4196** the extra prepFlags parameter, which is a bit array consisting of zero or 4197** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The 4198** sqlite3_prepare_v2() interface works exactly the same as 4199** sqlite3_prepare_v3() with a zero prepFlags parameter. 4200*/ 4201SQLITE_API int sqlite3_prepare( 4202 sqlite3 *db, /* Database handle */ 4203 const char *zSql, /* SQL statement, UTF-8 encoded */ 4204 int nByte, /* Maximum length of zSql in bytes. */ 4205 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4206 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4207); 4208SQLITE_API int sqlite3_prepare_v2( 4209 sqlite3 *db, /* Database handle */ 4210 const char *zSql, /* SQL statement, UTF-8 encoded */ 4211 int nByte, /* Maximum length of zSql in bytes. */ 4212 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4213 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4214); 4215SQLITE_API int sqlite3_prepare_v3( 4216 sqlite3 *db, /* Database handle */ 4217 const char *zSql, /* SQL statement, UTF-8 encoded */ 4218 int nByte, /* Maximum length of zSql in bytes. */ 4219 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4220 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4221 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 4222); 4223SQLITE_API int sqlite3_prepare16( 4224 sqlite3 *db, /* Database handle */ 4225 const void *zSql, /* SQL statement, UTF-16 encoded */ 4226 int nByte, /* Maximum length of zSql in bytes. */ 4227 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4228 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4229); 4230SQLITE_API int sqlite3_prepare16_v2( 4231 sqlite3 *db, /* Database handle */ 4232 const void *zSql, /* SQL statement, UTF-16 encoded */ 4233 int nByte, /* Maximum length of zSql in bytes. */ 4234 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4235 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4236); 4237SQLITE_API int sqlite3_prepare16_v3( 4238 sqlite3 *db, /* Database handle */ 4239 const void *zSql, /* SQL statement, UTF-16 encoded */ 4240 int nByte, /* Maximum length of zSql in bytes. */ 4241 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 4242 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 4243 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 4244); 4245 4246/* 4247** CAPI3REF: Retrieving Statement SQL 4248** METHOD: sqlite3_stmt 4249** 4250** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 4251** SQL text used to create [prepared statement] P if P was 4252** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 4253** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4254** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 4255** string containing the SQL text of prepared statement P with 4256** [bound parameters] expanded. 4257** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8 4258** string containing the normalized SQL text of prepared statement P. The 4259** semantics used to normalize a SQL statement are unspecified and subject 4260** to change. At a minimum, literal values will be replaced with suitable 4261** placeholders. 4262** 4263** ^(For example, if a prepared statement is created using the SQL 4264** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 4265** and parameter :xyz is unbound, then sqlite3_sql() will return 4266** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 4267** will return "SELECT 2345,NULL".)^ 4268** 4269** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 4270** is available to hold the result, or if the result would exceed the 4271** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 4272** 4273** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 4274** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 4275** option causes sqlite3_expanded_sql() to always return NULL. 4276** 4277** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P) 4278** are managed by SQLite and are automatically freed when the prepared 4279** statement is finalized. 4280** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 4281** is obtained from [sqlite3_malloc()] and must be freed by the application 4282** by passing it to [sqlite3_free()]. 4283** 4284** ^The sqlite3_normalized_sql() interface is only available if 4285** the [SQLITE_ENABLE_NORMALIZE] compile-time option is defined. 4286*/ 4287SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 4288SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 4289#ifdef SQLITE_ENABLE_NORMALIZE 4290SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt); 4291#endif 4292 4293/* 4294** CAPI3REF: Determine If An SQL Statement Writes The Database 4295** METHOD: sqlite3_stmt 4296** 4297** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 4298** and only if the [prepared statement] X makes no direct changes to 4299** the content of the database file. 4300** 4301** Note that [application-defined SQL functions] or 4302** [virtual tables] might change the database indirectly as a side effect. 4303** ^(For example, if an application defines a function "eval()" that 4304** calls [sqlite3_exec()], then the following SQL statement would 4305** change the database file through side-effects: 4306** 4307** <blockquote><pre> 4308** SELECT eval('DELETE FROM t1') FROM t2; 4309** </pre></blockquote> 4310** 4311** But because the [SELECT] statement does not change the database file 4312** directly, sqlite3_stmt_readonly() would still return true.)^ 4313** 4314** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 4315** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 4316** since the statements themselves do not actually modify the database but 4317** rather they control the timing of when other statements modify the 4318** database. ^The [ATTACH] and [DETACH] statements also cause 4319** sqlite3_stmt_readonly() to return true since, while those statements 4320** change the configuration of a database connection, they do not make 4321** changes to the content of the database files on disk. 4322** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 4323** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 4324** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 4325** sqlite3_stmt_readonly() returns false for those commands. 4326** 4327** ^This routine returns false if there is any possibility that the 4328** statement might change the database file. ^A false return does 4329** not guarantee that the statement will change the database file. 4330** ^For example, an UPDATE statement might have a WHERE clause that 4331** makes it a no-op, but the sqlite3_stmt_readonly() result would still 4332** be false. ^Similarly, a CREATE TABLE IF NOT EXISTS statement is a 4333** read-only no-op if the table already exists, but 4334** sqlite3_stmt_readonly() still returns false for such a statement. 4335** 4336** ^If prepared statement X is an [EXPLAIN] or [EXPLAIN QUERY PLAN] 4337** statement, then sqlite3_stmt_readonly(X) returns the same value as 4338** if the EXPLAIN or EXPLAIN QUERY PLAN prefix were omitted. 4339*/ 4340SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 4341 4342/* 4343** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement 4344** METHOD: sqlite3_stmt 4345** 4346** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the 4347** prepared statement S is an EXPLAIN statement, or 2 if the 4348** statement S is an EXPLAIN QUERY PLAN. 4349** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is 4350** an ordinary statement or a NULL pointer. 4351*/ 4352SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt); 4353 4354/* 4355** CAPI3REF: Determine If A Prepared Statement Has Been Reset 4356** METHOD: sqlite3_stmt 4357** 4358** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 4359** [prepared statement] S has been stepped at least once using 4360** [sqlite3_step(S)] but has neither run to completion (returned 4361** [SQLITE_DONE] from [sqlite3_step(S)]) nor 4362** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 4363** interface returns false if S is a NULL pointer. If S is not a 4364** NULL pointer and is not a pointer to a valid [prepared statement] 4365** object, then the behavior is undefined and probably undesirable. 4366** 4367** This interface can be used in combination [sqlite3_next_stmt()] 4368** to locate all prepared statements associated with a database 4369** connection that are in need of being reset. This can be used, 4370** for example, in diagnostic routines to search for prepared 4371** statements that are holding a transaction open. 4372*/ 4373SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); 4374 4375/* 4376** CAPI3REF: Dynamically Typed Value Object 4377** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 4378** 4379** SQLite uses the sqlite3_value object to represent all values 4380** that can be stored in a database table. SQLite uses dynamic typing 4381** for the values it stores. ^Values stored in sqlite3_value objects 4382** can be integers, floating point values, strings, BLOBs, or NULL. 4383** 4384** An sqlite3_value object may be either "protected" or "unprotected". 4385** Some interfaces require a protected sqlite3_value. Other interfaces 4386** will accept either a protected or an unprotected sqlite3_value. 4387** Every interface that accepts sqlite3_value arguments specifies 4388** whether or not it requires a protected sqlite3_value. The 4389** [sqlite3_value_dup()] interface can be used to construct a new 4390** protected sqlite3_value from an unprotected sqlite3_value. 4391** 4392** The terms "protected" and "unprotected" refer to whether or not 4393** a mutex is held. An internal mutex is held for a protected 4394** sqlite3_value object but no mutex is held for an unprotected 4395** sqlite3_value object. If SQLite is compiled to be single-threaded 4396** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 4397** or if SQLite is run in one of reduced mutex modes 4398** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 4399** then there is no distinction between protected and unprotected 4400** sqlite3_value objects and they can be used interchangeably. However, 4401** for maximum code portability it is recommended that applications 4402** still make the distinction between protected and unprotected 4403** sqlite3_value objects even when not strictly required. 4404** 4405** ^The sqlite3_value objects that are passed as parameters into the 4406** implementation of [application-defined SQL functions] are protected. 4407** ^The sqlite3_value objects returned by [sqlite3_vtab_rhs_value()] 4408** are protected. 4409** ^The sqlite3_value object returned by 4410** [sqlite3_column_value()] is unprotected. 4411** Unprotected sqlite3_value objects may only be used as arguments 4412** to [sqlite3_result_value()], [sqlite3_bind_value()], and 4413** [sqlite3_value_dup()]. 4414** The [sqlite3_value_blob | sqlite3_value_type()] family of 4415** interfaces require protected sqlite3_value objects. 4416*/ 4417typedef struct sqlite3_value sqlite3_value; 4418 4419/* 4420** CAPI3REF: SQL Function Context Object 4421** 4422** The context in which an SQL function executes is stored in an 4423** sqlite3_context object. ^A pointer to an sqlite3_context object 4424** is always first parameter to [application-defined SQL functions]. 4425** The application-defined SQL function implementation will pass this 4426** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 4427** [sqlite3_aggregate_context()], [sqlite3_user_data()], 4428** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 4429** and/or [sqlite3_set_auxdata()]. 4430*/ 4431typedef struct sqlite3_context sqlite3_context; 4432 4433/* 4434** CAPI3REF: Binding Values To Prepared Statements 4435** KEYWORDS: {host parameter} {host parameters} {host parameter name} 4436** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 4437** METHOD: sqlite3_stmt 4438** 4439** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 4440** literals may be replaced by a [parameter] that matches one of following 4441** templates: 4442** 4443** <ul> 4444** <li> ? 4445** <li> ?NNN 4446** <li> :VVV 4447** <li> @VVV 4448** <li> $VVV 4449** </ul> 4450** 4451** In the templates above, NNN represents an integer literal, 4452** and VVV represents an alphanumeric identifier.)^ ^The values of these 4453** parameters (also called "host parameter names" or "SQL parameters") 4454** can be set using the sqlite3_bind_*() routines defined here. 4455** 4456** ^The first argument to the sqlite3_bind_*() routines is always 4457** a pointer to the [sqlite3_stmt] object returned from 4458** [sqlite3_prepare_v2()] or its variants. 4459** 4460** ^The second argument is the index of the SQL parameter to be set. 4461** ^The leftmost SQL parameter has an index of 1. ^When the same named 4462** SQL parameter is used more than once, second and subsequent 4463** occurrences have the same index as the first occurrence. 4464** ^The index for named parameters can be looked up using the 4465** [sqlite3_bind_parameter_index()] API if desired. ^The index 4466** for "?NNN" parameters is the value of NNN. 4467** ^The NNN value must be between 1 and the [sqlite3_limit()] 4468** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766). 4469** 4470** ^The third argument is the value to bind to the parameter. 4471** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4472** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 4473** is ignored and the end result is the same as sqlite3_bind_null(). 4474** ^If the third parameter to sqlite3_bind_text() is not NULL, then 4475** it should be a pointer to well-formed UTF8 text. 4476** ^If the third parameter to sqlite3_bind_text16() is not NULL, then 4477** it should be a pointer to well-formed UTF16 text. 4478** ^If the third parameter to sqlite3_bind_text64() is not NULL, then 4479** it should be a pointer to a well-formed unicode string that is 4480** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16 4481** otherwise. 4482** 4483** [[byte-order determination rules]] ^The byte-order of 4484** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF) 4485** found in first character, which is removed, or in the absence of a BOM 4486** the byte order is the native byte order of the host 4487** machine for sqlite3_bind_text16() or the byte order specified in 4488** the 6th parameter for sqlite3_bind_text64().)^ 4489** ^If UTF16 input text contains invalid unicode 4490** characters, then SQLite might change those invalid characters 4491** into the unicode replacement character: U+FFFD. 4492** 4493** ^(In those routines that have a fourth argument, its value is the 4494** number of bytes in the parameter. To be clear: the value is the 4495** number of <u>bytes</u> in the value, not the number of characters.)^ 4496** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4497** is negative, then the length of the string is 4498** the number of bytes up to the first zero terminator. 4499** If the fourth parameter to sqlite3_bind_blob() is negative, then 4500** the behavior is undefined. 4501** If a non-negative fourth parameter is provided to sqlite3_bind_text() 4502** or sqlite3_bind_text16() or sqlite3_bind_text64() then 4503** that parameter must be the byte offset 4504** where the NUL terminator would occur assuming the string were NUL 4505** terminated. If any NUL characters occurs at byte offsets less than 4506** the value of the fourth parameter then the resulting string value will 4507** contain embedded NULs. The result of expressions involving strings 4508** with embedded NULs is undefined. 4509** 4510** ^The fifth argument to the BLOB and string binding interfaces controls 4511** or indicates the lifetime of the object referenced by the third parameter. 4512** These three options exist: 4513** ^ (1) A destructor to dispose of the BLOB or string after SQLite has finished 4514** with it may be passed. ^It is called to dispose of the BLOB or string even 4515** if the call to the bind API fails, except the destructor is not called if 4516** the third parameter is a NULL pointer or the fourth parameter is negative. 4517** ^ (2) The special constant, [SQLITE_STATIC], may be passsed to indicate that 4518** the application remains responsible for disposing of the object. ^In this 4519** case, the object and the provided pointer to it must remain valid until 4520** either the prepared statement is finalized or the same SQL parameter is 4521** bound to something else, whichever occurs sooner. 4522** ^ (3) The constant, [SQLITE_TRANSIENT], may be passed to indicate that the 4523** object is to be copied prior to the return from sqlite3_bind_*(). ^The 4524** object and pointer to it must remain valid until then. ^SQLite will then 4525** manage the lifetime of its private copy. 4526** 4527** ^The sixth argument to sqlite3_bind_text64() must be one of 4528** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 4529** to specify the encoding of the text in the third parameter. If 4530** the sixth argument to sqlite3_bind_text64() is not one of the 4531** allowed values shown above, or if the text encoding is different 4532** from the encoding specified by the sixth parameter, then the behavior 4533** is undefined. 4534** 4535** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 4536** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 4537** (just an integer to hold its size) while it is being processed. 4538** Zeroblobs are intended to serve as placeholders for BLOBs whose 4539** content is later written using 4540** [sqlite3_blob_open | incremental BLOB I/O] routines. 4541** ^A negative value for the zeroblob results in a zero-length BLOB. 4542** 4543** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in 4544** [prepared statement] S to have an SQL value of NULL, but to also be 4545** associated with the pointer P of type T. ^D is either a NULL pointer or 4546** a pointer to a destructor function for P. ^SQLite will invoke the 4547** destructor D with a single argument of P when it is finished using 4548** P. The T parameter should be a static string, preferably a string 4549** literal. The sqlite3_bind_pointer() routine is part of the 4550** [pointer passing interface] added for SQLite 3.20.0. 4551** 4552** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 4553** for the [prepared statement] or with a prepared statement for which 4554** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 4555** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 4556** routine is passed a [prepared statement] that has been finalized, the 4557** result is undefined and probably harmful. 4558** 4559** ^Bindings are not cleared by the [sqlite3_reset()] routine. 4560** ^Unbound parameters are interpreted as NULL. 4561** 4562** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 4563** [error code] if anything goes wrong. 4564** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 4565** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 4566** [SQLITE_MAX_LENGTH]. 4567** ^[SQLITE_RANGE] is returned if the parameter 4568** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 4569** 4570** See also: [sqlite3_bind_parameter_count()], 4571** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 4572*/ 4573SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 4574SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 4575 void(*)(void*)); 4576SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 4577SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 4578SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 4579SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 4580SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 4581SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 4582SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 4583 void(*)(void*), unsigned char encoding); 4584SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 4585SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 4586SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 4587SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 4588 4589/* 4590** CAPI3REF: Number Of SQL Parameters 4591** METHOD: sqlite3_stmt 4592** 4593** ^This routine can be used to find the number of [SQL parameters] 4594** in a [prepared statement]. SQL parameters are tokens of the 4595** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 4596** placeholders for values that are [sqlite3_bind_blob | bound] 4597** to the parameters at a later time. 4598** 4599** ^(This routine actually returns the index of the largest (rightmost) 4600** parameter. For all forms except ?NNN, this will correspond to the 4601** number of unique parameters. If parameters of the ?NNN form are used, 4602** there may be gaps in the list.)^ 4603** 4604** See also: [sqlite3_bind_blob|sqlite3_bind()], 4605** [sqlite3_bind_parameter_name()], and 4606** [sqlite3_bind_parameter_index()]. 4607*/ 4608SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 4609 4610/* 4611** CAPI3REF: Name Of A Host Parameter 4612** METHOD: sqlite3_stmt 4613** 4614** ^The sqlite3_bind_parameter_name(P,N) interface returns 4615** the name of the N-th [SQL parameter] in the [prepared statement] P. 4616** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 4617** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 4618** respectively. 4619** In other words, the initial ":" or "$" or "@" or "?" 4620** is included as part of the name.)^ 4621** ^Parameters of the form "?" without a following integer have no name 4622** and are referred to as "nameless" or "anonymous parameters". 4623** 4624** ^The first host parameter has an index of 1, not 0. 4625** 4626** ^If the value N is out of range or if the N-th parameter is 4627** nameless, then NULL is returned. ^The returned string is 4628** always in UTF-8 encoding even if the named parameter was 4629** originally specified as UTF-16 in [sqlite3_prepare16()], 4630** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4631** 4632** See also: [sqlite3_bind_blob|sqlite3_bind()], 4633** [sqlite3_bind_parameter_count()], and 4634** [sqlite3_bind_parameter_index()]. 4635*/ 4636SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 4637 4638/* 4639** CAPI3REF: Index Of A Parameter With A Given Name 4640** METHOD: sqlite3_stmt 4641** 4642** ^Return the index of an SQL parameter given its name. ^The 4643** index value returned is suitable for use as the second 4644** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 4645** is returned if no matching parameter is found. ^The parameter 4646** name must be given in UTF-8 even if the original statement 4647** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 4648** [sqlite3_prepare16_v3()]. 4649** 4650** See also: [sqlite3_bind_blob|sqlite3_bind()], 4651** [sqlite3_bind_parameter_count()], and 4652** [sqlite3_bind_parameter_name()]. 4653*/ 4654SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 4655 4656/* 4657** CAPI3REF: Reset All Bindings On A Prepared Statement 4658** METHOD: sqlite3_stmt 4659** 4660** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 4661** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 4662** ^Use this routine to reset all host parameters to NULL. 4663*/ 4664SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 4665 4666/* 4667** CAPI3REF: Number Of Columns In A Result Set 4668** METHOD: sqlite3_stmt 4669** 4670** ^Return the number of columns in the result set returned by the 4671** [prepared statement]. ^If this routine returns 0, that means the 4672** [prepared statement] returns no data (for example an [UPDATE]). 4673** ^However, just because this routine returns a positive number does not 4674** mean that one or more rows of data will be returned. ^A SELECT statement 4675** will always have a positive sqlite3_column_count() but depending on the 4676** WHERE clause constraints and the table content, it might return no rows. 4677** 4678** See also: [sqlite3_data_count()] 4679*/ 4680SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 4681 4682/* 4683** CAPI3REF: Column Names In A Result Set 4684** METHOD: sqlite3_stmt 4685** 4686** ^These routines return the name assigned to a particular column 4687** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 4688** interface returns a pointer to a zero-terminated UTF-8 string 4689** and sqlite3_column_name16() returns a pointer to a zero-terminated 4690** UTF-16 string. ^The first parameter is the [prepared statement] 4691** that implements the [SELECT] statement. ^The second parameter is the 4692** column number. ^The leftmost column is number 0. 4693** 4694** ^The returned string pointer is valid until either the [prepared statement] 4695** is destroyed by [sqlite3_finalize()] or until the statement is automatically 4696** reprepared by the first call to [sqlite3_step()] for a particular run 4697** or until the next call to 4698** sqlite3_column_name() or sqlite3_column_name16() on the same column. 4699** 4700** ^If sqlite3_malloc() fails during the processing of either routine 4701** (for example during a conversion from UTF-8 to UTF-16) then a 4702** NULL pointer is returned. 4703** 4704** ^The name of a result column is the value of the "AS" clause for 4705** that column, if there is an AS clause. If there is no AS clause 4706** then the name of the column is unspecified and may change from 4707** one release of SQLite to the next. 4708*/ 4709SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 4710SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 4711 4712/* 4713** CAPI3REF: Source Of Data In A Query Result 4714** METHOD: sqlite3_stmt 4715** 4716** ^These routines provide a means to determine the database, table, and 4717** table column that is the origin of a particular result column in 4718** [SELECT] statement. 4719** ^The name of the database or table or column can be returned as 4720** either a UTF-8 or UTF-16 string. ^The _database_ routines return 4721** the database name, the _table_ routines return the table name, and 4722** the origin_ routines return the column name. 4723** ^The returned string is valid until the [prepared statement] is destroyed 4724** using [sqlite3_finalize()] or until the statement is automatically 4725** reprepared by the first call to [sqlite3_step()] for a particular run 4726** or until the same information is requested 4727** again in a different encoding. 4728** 4729** ^The names returned are the original un-aliased names of the 4730** database, table, and column. 4731** 4732** ^The first argument to these interfaces is a [prepared statement]. 4733** ^These functions return information about the Nth result column returned by 4734** the statement, where N is the second function argument. 4735** ^The left-most column is column 0 for these routines. 4736** 4737** ^If the Nth column returned by the statement is an expression or 4738** subquery and is not a column value, then all of these functions return 4739** NULL. ^These routines might also return NULL if a memory allocation error 4740** occurs. ^Otherwise, they return the name of the attached database, table, 4741** or column that query result column was extracted from. 4742** 4743** ^As with all other SQLite APIs, those whose names end with "16" return 4744** UTF-16 encoded strings and the other functions return UTF-8. 4745** 4746** ^These APIs are only available if the library was compiled with the 4747** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4748** 4749** If two or more threads call one or more 4750** [sqlite3_column_database_name | column metadata interfaces] 4751** for the same [prepared statement] and result column 4752** at the same time then the results are undefined. 4753*/ 4754SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4755SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4756SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4757SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4758SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4759SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4760 4761/* 4762** CAPI3REF: Declared Datatype Of A Query Result 4763** METHOD: sqlite3_stmt 4764** 4765** ^(The first parameter is a [prepared statement]. 4766** If this statement is a [SELECT] statement and the Nth column of the 4767** returned result set of that [SELECT] is a table column (not an 4768** expression or subquery) then the declared type of the table 4769** column is returned.)^ ^If the Nth column of the result set is an 4770** expression or subquery, then a NULL pointer is returned. 4771** ^The returned string is always UTF-8 encoded. 4772** 4773** ^(For example, given the database schema: 4774** 4775** CREATE TABLE t1(c1 VARIANT); 4776** 4777** and the following statement to be compiled: 4778** 4779** SELECT c1 + 1, c1 FROM t1; 4780** 4781** this routine would return the string "VARIANT" for the second result 4782** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4783** 4784** ^SQLite uses dynamic run-time typing. ^So just because a column 4785** is declared to contain a particular type does not mean that the 4786** data stored in that column is of the declared type. SQLite is 4787** strongly typed, but the typing is dynamic not static. ^Type 4788** is associated with individual values, not with the containers 4789** used to hold those values. 4790*/ 4791SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4792SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4793 4794/* 4795** CAPI3REF: Evaluate An SQL Statement 4796** METHOD: sqlite3_stmt 4797** 4798** After a [prepared statement] has been prepared using any of 4799** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], 4800** or [sqlite3_prepare16_v3()] or one of the legacy 4801** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4802** must be called one or more times to evaluate the statement. 4803** 4804** The details of the behavior of the sqlite3_step() interface depend 4805** on whether the statement was prepared using the newer "vX" interfaces 4806** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], 4807** [sqlite3_prepare16_v2()] or the older legacy 4808** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4809** new "vX" interface is recommended for new applications but the legacy 4810** interface will continue to be supported. 4811** 4812** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4813** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4814** ^With the "v2" interface, any of the other [result codes] or 4815** [extended result codes] might be returned as well. 4816** 4817** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4818** database locks it needs to do its job. ^If the statement is a [COMMIT] 4819** or occurs outside of an explicit transaction, then you can retry the 4820** statement. If the statement is not a [COMMIT] and occurs within an 4821** explicit transaction then you should rollback the transaction before 4822** continuing. 4823** 4824** ^[SQLITE_DONE] means that the statement has finished executing 4825** successfully. sqlite3_step() should not be called again on this virtual 4826** machine without first calling [sqlite3_reset()] to reset the virtual 4827** machine back to its initial state. 4828** 4829** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4830** is returned each time a new row of data is ready for processing by the 4831** caller. The values may be accessed using the [column access functions]. 4832** sqlite3_step() is called again to retrieve the next row of data. 4833** 4834** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4835** violation) has occurred. sqlite3_step() should not be called again on 4836** the VM. More information may be found by calling [sqlite3_errmsg()]. 4837** ^With the legacy interface, a more specific error code (for example, 4838** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4839** can be obtained by calling [sqlite3_reset()] on the 4840** [prepared statement]. ^In the "v2" interface, 4841** the more specific error code is returned directly by sqlite3_step(). 4842** 4843** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4844** Perhaps it was called on a [prepared statement] that has 4845** already been [sqlite3_finalize | finalized] or on one that had 4846** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4847** be the case that the same database connection is being used by two or 4848** more threads at the same moment in time. 4849** 4850** For all versions of SQLite up to and including 3.6.23.1, a call to 4851** [sqlite3_reset()] was required after sqlite3_step() returned anything 4852** other than [SQLITE_ROW] before any subsequent invocation of 4853** sqlite3_step(). Failure to reset the prepared statement using 4854** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4855** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4856** sqlite3_step() began 4857** calling [sqlite3_reset()] automatically in this circumstance rather 4858** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4859** break because any application that ever receives an SQLITE_MISUSE error 4860** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4861** can be used to restore the legacy behavior. 4862** 4863** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4864** API always returns a generic error code, [SQLITE_ERROR], following any 4865** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4866** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4867** specific [error codes] that better describes the error. 4868** We admit that this is a goofy design. The problem has been fixed 4869** with the "v2" interface. If you prepare all of your SQL statements 4870** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 4871** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 4872** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4873** then the more specific [error codes] are returned directly 4874** by sqlite3_step(). The use of the "vX" interfaces is recommended. 4875*/ 4876SQLITE_API int sqlite3_step(sqlite3_stmt*); 4877 4878/* 4879** CAPI3REF: Number of columns in a result set 4880** METHOD: sqlite3_stmt 4881** 4882** ^The sqlite3_data_count(P) interface returns the number of columns in the 4883** current row of the result set of [prepared statement] P. 4884** ^If prepared statement P does not have results ready to return 4885** (via calls to the [sqlite3_column_int | sqlite3_column()] family of 4886** interfaces) then sqlite3_data_count(P) returns 0. 4887** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4888** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4889** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4890** will return non-zero if previous call to [sqlite3_step](P) returned 4891** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4892** where it always returns zero since each step of that multi-step 4893** pragma returns 0 columns of data. 4894** 4895** See also: [sqlite3_column_count()] 4896*/ 4897SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 4898 4899/* 4900** CAPI3REF: Fundamental Datatypes 4901** KEYWORDS: SQLITE_TEXT 4902** 4903** ^(Every value in SQLite has one of five fundamental datatypes: 4904** 4905** <ul> 4906** <li> 64-bit signed integer 4907** <li> 64-bit IEEE floating point number 4908** <li> string 4909** <li> BLOB 4910** <li> NULL 4911** </ul>)^ 4912** 4913** These constants are codes for each of those types. 4914** 4915** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4916** for a completely different meaning. Software that links against both 4917** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4918** SQLITE_TEXT. 4919*/ 4920#define SQLITE_INTEGER 1 4921#define SQLITE_FLOAT 2 4922#define SQLITE_BLOB 4 4923#define SQLITE_NULL 5 4924#ifdef SQLITE_TEXT 4925# undef SQLITE_TEXT 4926#else 4927# define SQLITE_TEXT 3 4928#endif 4929#define SQLITE3_TEXT 3 4930 4931/* 4932** CAPI3REF: Result Values From A Query 4933** KEYWORDS: {column access functions} 4934** METHOD: sqlite3_stmt 4935** 4936** <b>Summary:</b> 4937** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4938** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result 4939** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result 4940** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result 4941** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result 4942** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result 4943** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result 4944** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an 4945** [sqlite3_value|unprotected sqlite3_value] object. 4946** <tr><td> <td> <td> 4947** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB 4948** or a UTF-8 TEXT result in bytes 4949** <tr><td><b>sqlite3_column_bytes16 </b> 4950** <td>→ <td>Size of UTF-16 4951** TEXT in bytes 4952** <tr><td><b>sqlite3_column_type</b><td>→<td>Default 4953** datatype of the result 4954** </table></blockquote> 4955** 4956** <b>Details:</b> 4957** 4958** ^These routines return information about a single column of the current 4959** result row of a query. ^In every case the first argument is a pointer 4960** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4961** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4962** and the second argument is the index of the column for which information 4963** should be returned. ^The leftmost column of the result set has the index 0. 4964** ^The number of columns in the result can be determined using 4965** [sqlite3_column_count()]. 4966** 4967** If the SQL statement does not currently point to a valid row, or if the 4968** column index is out of range, the result is undefined. 4969** These routines may only be called when the most recent call to 4970** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4971** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4972** If any of these routines are called after [sqlite3_reset()] or 4973** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4974** something other than [SQLITE_ROW], the results are undefined. 4975** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4976** are called from a different thread while any of these routines 4977** are pending, then the results are undefined. 4978** 4979** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) 4980** each return the value of a result column in a specific data format. If 4981** the result column is not initially in the requested format (for example, 4982** if the query returns an integer but the sqlite3_column_text() interface 4983** is used to extract the value) then an automatic type conversion is performed. 4984** 4985** ^The sqlite3_column_type() routine returns the 4986** [SQLITE_INTEGER | datatype code] for the initial data type 4987** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4988** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. 4989** The return value of sqlite3_column_type() can be used to decide which 4990** of the first six interface should be used to extract the column value. 4991** The value returned by sqlite3_column_type() is only meaningful if no 4992** automatic type conversions have occurred for the value in question. 4993** After a type conversion, the result of calling sqlite3_column_type() 4994** is undefined, though harmless. Future 4995** versions of SQLite may change the behavior of sqlite3_column_type() 4996** following a type conversion. 4997** 4998** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() 4999** or sqlite3_column_bytes16() interfaces can be used to determine the size 5000** of that BLOB or string. 5001** 5002** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 5003** routine returns the number of bytes in that BLOB or string. 5004** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 5005** the string to UTF-8 and then returns the number of bytes. 5006** ^If the result is a numeric value then sqlite3_column_bytes() uses 5007** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 5008** the number of bytes in that string. 5009** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 5010** 5011** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 5012** routine returns the number of bytes in that BLOB or string. 5013** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 5014** the string to UTF-16 and then returns the number of bytes. 5015** ^If the result is a numeric value then sqlite3_column_bytes16() uses 5016** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 5017** the number of bytes in that string. 5018** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 5019** 5020** ^The values returned by [sqlite3_column_bytes()] and 5021** [sqlite3_column_bytes16()] do not include the zero terminators at the end 5022** of the string. ^For clarity: the values returned by 5023** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 5024** bytes in the string, not the number of characters. 5025** 5026** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 5027** even empty strings, are always zero-terminated. ^The return 5028** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 5029** 5030** ^Strings returned by sqlite3_column_text16() always have the endianness 5031** which is native to the platform, regardless of the text encoding set 5032** for the database. 5033** 5034** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 5035** [unprotected sqlite3_value] object. In a multithreaded environment, 5036** an unprotected sqlite3_value object may only be used safely with 5037** [sqlite3_bind_value()] and [sqlite3_result_value()]. 5038** If the [unprotected sqlite3_value] object returned by 5039** [sqlite3_column_value()] is used in any other way, including calls 5040** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 5041** or [sqlite3_value_bytes()], the behavior is not threadsafe. 5042** Hence, the sqlite3_column_value() interface 5043** is normally only useful within the implementation of 5044** [application-defined SQL functions] or [virtual tables], not within 5045** top-level application code. 5046** 5047** These routines may attempt to convert the datatype of the result. 5048** ^For example, if the internal representation is FLOAT and a text result 5049** is requested, [sqlite3_snprintf()] is used internally to perform the 5050** conversion automatically. ^(The following table details the conversions 5051** that are applied: 5052** 5053** <blockquote> 5054** <table border="1"> 5055** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 5056** 5057** <tr><td> NULL <td> INTEGER <td> Result is 0 5058** <tr><td> NULL <td> FLOAT <td> Result is 0.0 5059** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 5060** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 5061** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 5062** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 5063** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 5064** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 5065** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 5066** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 5067** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 5068** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 5069** <tr><td> TEXT <td> BLOB <td> No change 5070** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 5071** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 5072** <tr><td> BLOB <td> TEXT <td> [CAST] to TEXT, ensure zero terminator 5073** </table> 5074** </blockquote>)^ 5075** 5076** Note that when type conversions occur, pointers returned by prior 5077** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 5078** sqlite3_column_text16() may be invalidated. 5079** Type conversions and pointer invalidations might occur 5080** in the following cases: 5081** 5082** <ul> 5083** <li> The initial content is a BLOB and sqlite3_column_text() or 5084** sqlite3_column_text16() is called. A zero-terminator might 5085** need to be added to the string.</li> 5086** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 5087** sqlite3_column_text16() is called. The content must be converted 5088** to UTF-16.</li> 5089** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 5090** sqlite3_column_text() is called. The content must be converted 5091** to UTF-8.</li> 5092** </ul> 5093** 5094** ^Conversions between UTF-16be and UTF-16le are always done in place and do 5095** not invalidate a prior pointer, though of course the content of the buffer 5096** that the prior pointer references will have been modified. Other kinds 5097** of conversion are done in place when it is possible, but sometimes they 5098** are not possible and in those cases prior pointers are invalidated. 5099** 5100** The safest policy is to invoke these routines 5101** in one of the following ways: 5102** 5103** <ul> 5104** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 5105** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 5106** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 5107** </ul> 5108** 5109** In other words, you should call sqlite3_column_text(), 5110** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 5111** into the desired format, then invoke sqlite3_column_bytes() or 5112** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 5113** to sqlite3_column_text() or sqlite3_column_blob() with calls to 5114** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 5115** with calls to sqlite3_column_bytes(). 5116** 5117** ^The pointers returned are valid until a type conversion occurs as 5118** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 5119** [sqlite3_finalize()] is called. ^The memory space used to hold strings 5120** and BLOBs is freed automatically. Do not pass the pointers returned 5121** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 5122** [sqlite3_free()]. 5123** 5124** As long as the input parameters are correct, these routines will only 5125** fail if an out-of-memory error occurs during a format conversion. 5126** Only the following subset of interfaces are subject to out-of-memory 5127** errors: 5128** 5129** <ul> 5130** <li> sqlite3_column_blob() 5131** <li> sqlite3_column_text() 5132** <li> sqlite3_column_text16() 5133** <li> sqlite3_column_bytes() 5134** <li> sqlite3_column_bytes16() 5135** </ul> 5136** 5137** If an out-of-memory error occurs, then the return value from these 5138** routines is the same as if the column had contained an SQL NULL value. 5139** Valid SQL NULL returns can be distinguished from out-of-memory errors 5140** by invoking the [sqlite3_errcode()] immediately after the suspect 5141** return value is obtained and before any 5142** other SQLite interface is called on the same [database connection]. 5143*/ 5144SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 5145SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 5146SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 5147SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 5148SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 5149SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 5150SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 5151SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 5152SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 5153SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 5154 5155/* 5156** CAPI3REF: Destroy A Prepared Statement Object 5157** DESTRUCTOR: sqlite3_stmt 5158** 5159** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 5160** ^If the most recent evaluation of the statement encountered no errors 5161** or if the statement is never been evaluated, then sqlite3_finalize() returns 5162** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 5163** sqlite3_finalize(S) returns the appropriate [error code] or 5164** [extended error code]. 5165** 5166** ^The sqlite3_finalize(S) routine can be called at any point during 5167** the life cycle of [prepared statement] S: 5168** before statement S is ever evaluated, after 5169** one or more calls to [sqlite3_reset()], or after any call 5170** to [sqlite3_step()] regardless of whether or not the statement has 5171** completed execution. 5172** 5173** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 5174** 5175** The application must finalize every [prepared statement] in order to avoid 5176** resource leaks. It is a grievous error for the application to try to use 5177** a prepared statement after it has been finalized. Any use of a prepared 5178** statement after it has been finalized can result in undefined and 5179** undesirable behavior such as segfaults and heap corruption. 5180*/ 5181SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 5182 5183/* 5184** CAPI3REF: Reset A Prepared Statement Object 5185** METHOD: sqlite3_stmt 5186** 5187** The sqlite3_reset() function is called to reset a [prepared statement] 5188** object back to its initial state, ready to be re-executed. 5189** ^Any SQL statement variables that had values bound to them using 5190** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 5191** Use [sqlite3_clear_bindings()] to reset the bindings. 5192** 5193** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 5194** back to the beginning of its program. 5195** 5196** ^If the most recent call to [sqlite3_step(S)] for the 5197** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 5198** or if [sqlite3_step(S)] has never before been called on S, 5199** then [sqlite3_reset(S)] returns [SQLITE_OK]. 5200** 5201** ^If the most recent call to [sqlite3_step(S)] for the 5202** [prepared statement] S indicated an error, then 5203** [sqlite3_reset(S)] returns an appropriate [error code]. 5204** 5205** ^The [sqlite3_reset(S)] interface does not change the values 5206** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 5207*/ 5208SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 5209 5210/* 5211** CAPI3REF: Create Or Redefine SQL Functions 5212** KEYWORDS: {function creation routines} 5213** METHOD: sqlite3 5214** 5215** ^These functions (collectively known as "function creation routines") 5216** are used to add SQL functions or aggregates or to redefine the behavior 5217** of existing SQL functions or aggregates. The only differences between 5218** the three "sqlite3_create_function*" routines are the text encoding 5219** expected for the second parameter (the name of the function being 5220** created) and the presence or absence of a destructor callback for 5221** the application data pointer. Function sqlite3_create_window_function() 5222** is similar, but allows the user to supply the extra callback functions 5223** needed by [aggregate window functions]. 5224** 5225** ^The first parameter is the [database connection] to which the SQL 5226** function is to be added. ^If an application uses more than one database 5227** connection then application-defined SQL functions must be added 5228** to each database connection separately. 5229** 5230** ^The second parameter is the name of the SQL function to be created or 5231** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 5232** representation, exclusive of the zero-terminator. ^Note that the name 5233** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 5234** ^Any attempt to create a function with a longer name 5235** will result in [SQLITE_MISUSE] being returned. 5236** 5237** ^The third parameter (nArg) 5238** is the number of arguments that the SQL function or 5239** aggregate takes. ^If this parameter is -1, then the SQL function or 5240** aggregate may take any number of arguments between 0 and the limit 5241** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 5242** parameter is less than -1 or greater than 127 then the behavior is 5243** undefined. 5244** 5245** ^The fourth parameter, eTextRep, specifies what 5246** [SQLITE_UTF8 | text encoding] this SQL function prefers for 5247** its parameters. The application should set this parameter to 5248** [SQLITE_UTF16LE] if the function implementation invokes 5249** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 5250** implementation invokes [sqlite3_value_text16be()] on an input, or 5251** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 5252** otherwise. ^The same SQL function may be registered multiple times using 5253** different preferred text encodings, with different implementations for 5254** each encoding. 5255** ^When multiple implementations of the same function are available, SQLite 5256** will pick the one that involves the least amount of data conversion. 5257** 5258** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 5259** to signal that the function will always return the same result given 5260** the same inputs within a single SQL statement. Most SQL functions are 5261** deterministic. The built-in [random()] SQL function is an example of a 5262** function that is not deterministic. The SQLite query planner is able to 5263** perform additional optimizations on deterministic functions, so use 5264** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 5265** 5266** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY] 5267** flag, which if present prevents the function from being invoked from 5268** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions, 5269** index expressions, or the WHERE clause of partial indexes. 5270** 5271** For best security, the [SQLITE_DIRECTONLY] flag is recommended for 5272** all application-defined SQL functions that do not need to be 5273** used inside of triggers, view, CHECK constraints, or other elements of 5274** the database schema. This flags is especially recommended for SQL 5275** functions that have side effects or reveal internal application state. 5276** Without this flag, an attacker might be able to modify the schema of 5277** a database file to include invocations of the function with parameters 5278** chosen by the attacker, which the application will then execute when 5279** the database file is opened and read. 5280** 5281** ^(The fifth parameter is an arbitrary pointer. The implementation of the 5282** function can gain access to this pointer using [sqlite3_user_data()].)^ 5283** 5284** ^The sixth, seventh and eighth parameters passed to the three 5285** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are 5286** pointers to C-language functions that implement the SQL function or 5287** aggregate. ^A scalar SQL function requires an implementation of the xFunc 5288** callback only; NULL pointers must be passed as the xStep and xFinal 5289** parameters. ^An aggregate SQL function requires an implementation of xStep 5290** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 5291** SQL function or aggregate, pass NULL pointers for all three function 5292** callbacks. 5293** 5294** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue 5295** and xInverse) passed to sqlite3_create_window_function are pointers to 5296** C-language callbacks that implement the new function. xStep and xFinal 5297** must both be non-NULL. xValue and xInverse may either both be NULL, in 5298** which case a regular aggregate function is created, or must both be 5299** non-NULL, in which case the new function may be used as either an aggregate 5300** or aggregate window function. More details regarding the implementation 5301** of aggregate window functions are 5302** [user-defined window functions|available here]. 5303** 5304** ^(If the final parameter to sqlite3_create_function_v2() or 5305** sqlite3_create_window_function() is not NULL, then it is destructor for 5306** the application data pointer. The destructor is invoked when the function 5307** is deleted, either by being overloaded or when the database connection 5308** closes.)^ ^The destructor is also invoked if the call to 5309** sqlite3_create_function_v2() fails. ^When the destructor callback is 5310** invoked, it is passed a single argument which is a copy of the application 5311** data pointer which was the fifth parameter to sqlite3_create_function_v2(). 5312** 5313** ^It is permitted to register multiple implementations of the same 5314** functions with the same name but with either differing numbers of 5315** arguments or differing preferred text encodings. ^SQLite will use 5316** the implementation that most closely matches the way in which the 5317** SQL function is used. ^A function implementation with a non-negative 5318** nArg parameter is a better match than a function implementation with 5319** a negative nArg. ^A function where the preferred text encoding 5320** matches the database encoding is a better 5321** match than a function where the encoding is different. 5322** ^A function where the encoding difference is between UTF16le and UTF16be 5323** is a closer match than a function where the encoding difference is 5324** between UTF8 and UTF16. 5325** 5326** ^Built-in functions may be overloaded by new application-defined functions. 5327** 5328** ^An application-defined function is permitted to call other 5329** SQLite interfaces. However, such calls must not 5330** close the database connection nor finalize or reset the prepared 5331** statement in which the function is running. 5332*/ 5333SQLITE_API int sqlite3_create_function( 5334 sqlite3 *db, 5335 const char *zFunctionName, 5336 int nArg, 5337 int eTextRep, 5338 void *pApp, 5339 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5340 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5341 void (*xFinal)(sqlite3_context*) 5342); 5343SQLITE_API int sqlite3_create_function16( 5344 sqlite3 *db, 5345 const void *zFunctionName, 5346 int nArg, 5347 int eTextRep, 5348 void *pApp, 5349 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5350 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5351 void (*xFinal)(sqlite3_context*) 5352); 5353SQLITE_API int sqlite3_create_function_v2( 5354 sqlite3 *db, 5355 const char *zFunctionName, 5356 int nArg, 5357 int eTextRep, 5358 void *pApp, 5359 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5360 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5361 void (*xFinal)(sqlite3_context*), 5362 void(*xDestroy)(void*) 5363); 5364SQLITE_API int sqlite3_create_window_function( 5365 sqlite3 *db, 5366 const char *zFunctionName, 5367 int nArg, 5368 int eTextRep, 5369 void *pApp, 5370 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5371 void (*xFinal)(sqlite3_context*), 5372 void (*xValue)(sqlite3_context*), 5373 void (*xInverse)(sqlite3_context*,int,sqlite3_value**), 5374 void(*xDestroy)(void*) 5375); 5376 5377/* 5378** CAPI3REF: Text Encodings 5379** 5380** These constant define integer codes that represent the various 5381** text encodings supported by SQLite. 5382*/ 5383#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 5384#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 5385#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 5386#define SQLITE_UTF16 4 /* Use native byte order */ 5387#define SQLITE_ANY 5 /* Deprecated */ 5388#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 5389 5390/* 5391** CAPI3REF: Function Flags 5392** 5393** These constants may be ORed together with the 5394** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 5395** to [sqlite3_create_function()], [sqlite3_create_function16()], or 5396** [sqlite3_create_function_v2()]. 5397** 5398** <dl> 5399** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd> 5400** The SQLITE_DETERMINISTIC flag means that the new function always gives 5401** the same output when the input parameters are the same. 5402** The [abs|abs() function] is deterministic, for example, but 5403** [randomblob|randomblob()] is not. Functions must 5404** be deterministic in order to be used in certain contexts such as 5405** with the WHERE clause of [partial indexes] or in [generated columns]. 5406** SQLite might also optimize deterministic functions by factoring them 5407** out of inner loops. 5408** </dd> 5409** 5410** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd> 5411** The SQLITE_DIRECTONLY flag means that the function may only be invoked 5412** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in 5413** schema structures such as [CHECK constraints], [DEFAULT clauses], 5414** [expression indexes], [partial indexes], or [generated columns]. 5415** The SQLITE_DIRECTONLY flags is a security feature which is recommended 5416** for all [application-defined SQL functions], and especially for functions 5417** that have side-effects or that could potentially leak sensitive 5418** information. 5419** </dd> 5420** 5421** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd> 5422** The SQLITE_INNOCUOUS flag means that the function is unlikely 5423** to cause problems even if misused. An innocuous function should have 5424** no side effects and should not depend on any values other than its 5425** input parameters. The [abs|abs() function] is an example of an 5426** innocuous function. 5427** The [load_extension() SQL function] is not innocuous because of its 5428** side effects. 5429** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not 5430** exactly the same. The [random|random() function] is an example of a 5431** function that is innocuous but not deterministic. 5432** <p>Some heightened security settings 5433** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF]) 5434** disable the use of SQL functions inside views and triggers and in 5435** schema structures such as [CHECK constraints], [DEFAULT clauses], 5436** [expression indexes], [partial indexes], and [generated columns] unless 5437** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions 5438** are innocuous. Developers are advised to avoid using the 5439** SQLITE_INNOCUOUS flag for application-defined functions unless the 5440** function has been carefully audited and found to be free of potentially 5441** security-adverse side-effects and information-leaks. 5442** </dd> 5443** 5444** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd> 5445** The SQLITE_SUBTYPE flag indicates to SQLite that a function may call 5446** [sqlite3_value_subtype()] to inspect the sub-types of its arguments. 5447** Specifying this flag makes no difference for scalar or aggregate user 5448** functions. However, if it is not specified for a user-defined window 5449** function, then any sub-types belonging to arguments passed to the window 5450** function may be discarded before the window function is called (i.e. 5451** sqlite3_value_subtype() will always return 0). 5452** </dd> 5453** </dl> 5454*/ 5455#define SQLITE_DETERMINISTIC 0x000000800 5456#define SQLITE_DIRECTONLY 0x000080000 5457#define SQLITE_SUBTYPE 0x000100000 5458#define SQLITE_INNOCUOUS 0x000200000 5459 5460/* 5461** CAPI3REF: Deprecated Functions 5462** DEPRECATED 5463** 5464** These functions are [deprecated]. In order to maintain 5465** backwards compatibility with older code, these functions continue 5466** to be supported. However, new applications should avoid 5467** the use of these functions. To encourage programmers to avoid 5468** these functions, we will not explain what they do. 5469*/ 5470#ifndef SQLITE_OMIT_DEPRECATED 5471SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 5472SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 5473SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 5474SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 5475SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 5476SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 5477 void*,sqlite3_int64); 5478#endif 5479 5480/* 5481** CAPI3REF: Obtaining SQL Values 5482** METHOD: sqlite3_value 5483** 5484** <b>Summary:</b> 5485** <blockquote><table border=0 cellpadding=0 cellspacing=0> 5486** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value 5487** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value 5488** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value 5489** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value 5490** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value 5491** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value 5492** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in 5493** the native byteorder 5494** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value 5495** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value 5496** <tr><td> <td> <td> 5497** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB 5498** or a UTF-8 TEXT in bytes 5499** <tr><td><b>sqlite3_value_bytes16 </b> 5500** <td>→ <td>Size of UTF-16 5501** TEXT in bytes 5502** <tr><td><b>sqlite3_value_type</b><td>→<td>Default 5503** datatype of the value 5504** <tr><td><b>sqlite3_value_numeric_type </b> 5505** <td>→ <td>Best numeric datatype of the value 5506** <tr><td><b>sqlite3_value_nochange </b> 5507** <td>→ <td>True if the column is unchanged in an UPDATE 5508** against a virtual table. 5509** <tr><td><b>sqlite3_value_frombind </b> 5510** <td>→ <td>True if value originated from a [bound parameter] 5511** </table></blockquote> 5512** 5513** <b>Details:</b> 5514** 5515** These routines extract type, size, and content information from 5516** [protected sqlite3_value] objects. Protected sqlite3_value objects 5517** are used to pass parameter information into the functions that 5518** implement [application-defined SQL functions] and [virtual tables]. 5519** 5520** These routines work only with [protected sqlite3_value] objects. 5521** Any attempt to use these routines on an [unprotected sqlite3_value] 5522** is not threadsafe. 5523** 5524** ^These routines work just like the corresponding [column access functions] 5525** except that these routines take a single [protected sqlite3_value] object 5526** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 5527** 5528** ^The sqlite3_value_text16() interface extracts a UTF-16 string 5529** in the native byte-order of the host machine. ^The 5530** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 5531** extract UTF-16 strings as big-endian and little-endian respectively. 5532** 5533** ^If [sqlite3_value] object V was initialized 5534** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] 5535** and if X and Y are strings that compare equal according to strcmp(X,Y), 5536** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, 5537** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 5538** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5539** 5540** ^(The sqlite3_value_type(V) interface returns the 5541** [SQLITE_INTEGER | datatype code] for the initial datatype of the 5542** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], 5543** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ 5544** Other interfaces might change the datatype for an sqlite3_value object. 5545** For example, if the datatype is initially SQLITE_INTEGER and 5546** sqlite3_value_text(V) is called to extract a text value for that 5547** integer, then subsequent calls to sqlite3_value_type(V) might return 5548** SQLITE_TEXT. Whether or not a persistent internal datatype conversion 5549** occurs is undefined and may change from one release of SQLite to the next. 5550** 5551** ^(The sqlite3_value_numeric_type() interface attempts to apply 5552** numeric affinity to the value. This means that an attempt is 5553** made to convert the value to an integer or floating point. If 5554** such a conversion is possible without loss of information (in other 5555** words, if the value is a string that looks like a number) 5556** then the conversion is performed. Otherwise no conversion occurs. 5557** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 5558** 5559** ^(The sqlite3_value_encoding(X) interface returns one of [SQLITE_UTF8], 5560** [SQLITE_UTF16BE], or [SQLITE_UTF16LE] according to the current encoding 5561** of the value X, assuming that X has type TEXT.)^ If sqlite3_value_type(X) 5562** returns something other than SQLITE_TEXT, then the return value from 5563** sqlite3_value_encoding(X) is meaningless. ^Calls to 5564** sqlite3_value_text(X), sqlite3_value_text16(X), sqlite3_value_text16be(X), 5565** sqlite3_value_text16le(X), sqlite3_value_bytes(X), or 5566** sqlite3_value_bytes16(X) might change the encoding of the value X and 5567** thus change the return from subsequent calls to sqlite3_value_encoding(X). 5568** 5569** ^Within the [xUpdate] method of a [virtual table], the 5570** sqlite3_value_nochange(X) interface returns true if and only if 5571** the column corresponding to X is unchanged by the UPDATE operation 5572** that the xUpdate method call was invoked to implement and if 5573** and the prior [xColumn] method call that was invoked to extracted 5574** the value for that column returned without setting a result (probably 5575** because it queried [sqlite3_vtab_nochange()] and found that the column 5576** was unchanging). ^Within an [xUpdate] method, any value for which 5577** sqlite3_value_nochange(X) is true will in all other respects appear 5578** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other 5579** than within an [xUpdate] method call for an UPDATE statement, then 5580** the return value is arbitrary and meaningless. 5581** 5582** ^The sqlite3_value_frombind(X) interface returns non-zero if the 5583** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()] 5584** interfaces. ^If X comes from an SQL literal value, or a table column, 5585** or an expression, then sqlite3_value_frombind(X) returns zero. 5586** 5587** Please pay particular attention to the fact that the pointer returned 5588** from [sqlite3_value_blob()], [sqlite3_value_text()], or 5589** [sqlite3_value_text16()] can be invalidated by a subsequent call to 5590** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 5591** or [sqlite3_value_text16()]. 5592** 5593** These routines must be called from the same thread as 5594** the SQL function that supplied the [sqlite3_value*] parameters. 5595** 5596** As long as the input parameter is correct, these routines can only 5597** fail if an out-of-memory error occurs during a format conversion. 5598** Only the following subset of interfaces are subject to out-of-memory 5599** errors: 5600** 5601** <ul> 5602** <li> sqlite3_value_blob() 5603** <li> sqlite3_value_text() 5604** <li> sqlite3_value_text16() 5605** <li> sqlite3_value_text16le() 5606** <li> sqlite3_value_text16be() 5607** <li> sqlite3_value_bytes() 5608** <li> sqlite3_value_bytes16() 5609** </ul> 5610** 5611** If an out-of-memory error occurs, then the return value from these 5612** routines is the same as if the column had contained an SQL NULL value. 5613** Valid SQL NULL returns can be distinguished from out-of-memory errors 5614** by invoking the [sqlite3_errcode()] immediately after the suspect 5615** return value is obtained and before any 5616** other SQLite interface is called on the same [database connection]. 5617*/ 5618SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 5619SQLITE_API double sqlite3_value_double(sqlite3_value*); 5620SQLITE_API int sqlite3_value_int(sqlite3_value*); 5621SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 5622SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*); 5623SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 5624SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 5625SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 5626SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 5627SQLITE_API int sqlite3_value_bytes(sqlite3_value*); 5628SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 5629SQLITE_API int sqlite3_value_type(sqlite3_value*); 5630SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 5631SQLITE_API int sqlite3_value_nochange(sqlite3_value*); 5632SQLITE_API int sqlite3_value_frombind(sqlite3_value*); 5633SQLITE_API int sqlite3_value_encoding(sqlite3_value*); 5634 5635/* 5636** CAPI3REF: Finding The Subtype Of SQL Values 5637** METHOD: sqlite3_value 5638** 5639** The sqlite3_value_subtype(V) function returns the subtype for 5640** an [application-defined SQL function] argument V. The subtype 5641** information can be used to pass a limited amount of context from 5642** one SQL function to another. Use the [sqlite3_result_subtype()] 5643** routine to set the subtype for the return value of an SQL function. 5644*/ 5645SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*); 5646 5647/* 5648** CAPI3REF: Copy And Free SQL Values 5649** METHOD: sqlite3_value 5650** 5651** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 5652** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 5653** is a [protected sqlite3_value] object even if the input is not. 5654** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 5655** memory allocation fails. ^If V is a [pointer value], then the result 5656** of sqlite3_value_dup(V) is a NULL value. 5657** 5658** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 5659** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 5660** then sqlite3_value_free(V) is a harmless no-op. 5661*/ 5662SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 5663SQLITE_API void sqlite3_value_free(sqlite3_value*); 5664 5665/* 5666** CAPI3REF: Obtain Aggregate Function Context 5667** METHOD: sqlite3_context 5668** 5669** Implementations of aggregate SQL functions use this 5670** routine to allocate memory for storing their state. 5671** 5672** ^The first time the sqlite3_aggregate_context(C,N) routine is called 5673** for a particular aggregate function, SQLite allocates 5674** N bytes of memory, zeroes out that memory, and returns a pointer 5675** to the new memory. ^On second and subsequent calls to 5676** sqlite3_aggregate_context() for the same aggregate function instance, 5677** the same buffer is returned. Sqlite3_aggregate_context() is normally 5678** called once for each invocation of the xStep callback and then one 5679** last time when the xFinal callback is invoked. ^(When no rows match 5680** an aggregate query, the xStep() callback of the aggregate function 5681** implementation is never called and xFinal() is called exactly once. 5682** In those cases, sqlite3_aggregate_context() might be called for the 5683** first time from within xFinal().)^ 5684** 5685** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 5686** when first called if N is less than or equal to zero or if a memory 5687** allocation error occurs. 5688** 5689** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 5690** determined by the N parameter on first successful call. Changing the 5691** value of N in any subsequent call to sqlite3_aggregate_context() within 5692** the same aggregate function instance will not resize the memory 5693** allocation.)^ Within the xFinal callback, it is customary to set 5694** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 5695** pointless memory allocations occur. 5696** 5697** ^SQLite automatically frees the memory allocated by 5698** sqlite3_aggregate_context() when the aggregate query concludes. 5699** 5700** The first parameter must be a copy of the 5701** [sqlite3_context | SQL function context] that is the first parameter 5702** to the xStep or xFinal callback routine that implements the aggregate 5703** function. 5704** 5705** This routine must be called from the same thread in which 5706** the aggregate SQL function is running. 5707*/ 5708SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 5709 5710/* 5711** CAPI3REF: User Data For Functions 5712** METHOD: sqlite3_context 5713** 5714** ^The sqlite3_user_data() interface returns a copy of 5715** the pointer that was the pUserData parameter (the 5th parameter) 5716** of the [sqlite3_create_function()] 5717** and [sqlite3_create_function16()] routines that originally 5718** registered the application defined function. 5719** 5720** This routine must be called from the same thread in which 5721** the application-defined function is running. 5722*/ 5723SQLITE_API void *sqlite3_user_data(sqlite3_context*); 5724 5725/* 5726** CAPI3REF: Database Connection For Functions 5727** METHOD: sqlite3_context 5728** 5729** ^The sqlite3_context_db_handle() interface returns a copy of 5730** the pointer to the [database connection] (the 1st parameter) 5731** of the [sqlite3_create_function()] 5732** and [sqlite3_create_function16()] routines that originally 5733** registered the application defined function. 5734*/ 5735SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 5736 5737/* 5738** CAPI3REF: Function Auxiliary Data 5739** METHOD: sqlite3_context 5740** 5741** These functions may be used by (non-aggregate) SQL functions to 5742** associate metadata with argument values. If the same value is passed to 5743** multiple invocations of the same SQL function during query execution, under 5744** some circumstances the associated metadata may be preserved. An example 5745** of where this might be useful is in a regular-expression matching 5746** function. The compiled version of the regular expression can be stored as 5747** metadata associated with the pattern string. 5748** Then as long as the pattern string remains the same, 5749** the compiled regular expression can be reused on multiple 5750** invocations of the same function. 5751** 5752** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata 5753** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 5754** value to the application-defined function. ^N is zero for the left-most 5755** function argument. ^If there is no metadata 5756** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 5757** returns a NULL pointer. 5758** 5759** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 5760** argument of the application-defined function. ^Subsequent 5761** calls to sqlite3_get_auxdata(C,N) return P from the most recent 5762** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 5763** NULL if the metadata has been discarded. 5764** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 5765** SQLite will invoke the destructor function X with parameter P exactly 5766** once, when the metadata is discarded. 5767** SQLite is free to discard the metadata at any time, including: <ul> 5768** <li> ^(when the corresponding function parameter changes)^, or 5769** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 5770** SQL statement)^, or 5771** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 5772** parameter)^, or 5773** <li> ^(during the original sqlite3_set_auxdata() call when a memory 5774** allocation error occurs.)^ </ul> 5775** 5776** Note the last bullet in particular. The destructor X in 5777** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 5778** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 5779** should be called near the end of the function implementation and the 5780** function implementation should not make any use of P after 5781** sqlite3_set_auxdata() has been called. 5782** 5783** ^(In practice, metadata is preserved between function calls for 5784** function parameters that are compile-time constants, including literal 5785** values and [parameters] and expressions composed from the same.)^ 5786** 5787** The value of the N parameter to these interfaces should be non-negative. 5788** Future enhancements may make use of negative N values to define new 5789** kinds of function caching behavior. 5790** 5791** These routines must be called from the same thread in which 5792** the SQL function is running. 5793*/ 5794SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 5795SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 5796 5797 5798/* 5799** CAPI3REF: Constants Defining Special Destructor Behavior 5800** 5801** These are special values for the destructor that is passed in as the 5802** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 5803** argument is SQLITE_STATIC, it means that the content pointer is constant 5804** and will never change. It does not need to be destroyed. ^The 5805** SQLITE_TRANSIENT value means that the content will likely change in 5806** the near future and that SQLite should make its own private copy of 5807** the content before returning. 5808** 5809** The typedef is necessary to work around problems in certain 5810** C++ compilers. 5811*/ 5812typedef void (*sqlite3_destructor_type)(void*); 5813#define SQLITE_STATIC ((sqlite3_destructor_type)0) 5814#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 5815 5816/* 5817** CAPI3REF: Setting The Result Of An SQL Function 5818** METHOD: sqlite3_context 5819** 5820** These routines are used by the xFunc or xFinal callbacks that 5821** implement SQL functions and aggregates. See 5822** [sqlite3_create_function()] and [sqlite3_create_function16()] 5823** for additional information. 5824** 5825** These functions work very much like the [parameter binding] family of 5826** functions used to bind values to host parameters in prepared statements. 5827** Refer to the [SQL parameter] documentation for additional information. 5828** 5829** ^The sqlite3_result_blob() interface sets the result from 5830** an application-defined function to be the BLOB whose content is pointed 5831** to by the second parameter and which is N bytes long where N is the 5832** third parameter. 5833** 5834** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 5835** interfaces set the result of the application-defined function to be 5836** a BLOB containing all zero bytes and N bytes in size. 5837** 5838** ^The sqlite3_result_double() interface sets the result from 5839** an application-defined function to be a floating point value specified 5840** by its 2nd argument. 5841** 5842** ^The sqlite3_result_error() and sqlite3_result_error16() functions 5843** cause the implemented SQL function to throw an exception. 5844** ^SQLite uses the string pointed to by the 5845** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 5846** as the text of an error message. ^SQLite interprets the error 5847** message string from sqlite3_result_error() as UTF-8. ^SQLite 5848** interprets the string from sqlite3_result_error16() as UTF-16 using 5849** the same [byte-order determination rules] as [sqlite3_bind_text16()]. 5850** ^If the third parameter to sqlite3_result_error() 5851** or sqlite3_result_error16() is negative then SQLite takes as the error 5852** message all text up through the first zero character. 5853** ^If the third parameter to sqlite3_result_error() or 5854** sqlite3_result_error16() is non-negative then SQLite takes that many 5855** bytes (not characters) from the 2nd parameter as the error message. 5856** ^The sqlite3_result_error() and sqlite3_result_error16() 5857** routines make a private copy of the error message text before 5858** they return. Hence, the calling function can deallocate or 5859** modify the text after they return without harm. 5860** ^The sqlite3_result_error_code() function changes the error code 5861** returned by SQLite as a result of an error in a function. ^By default, 5862** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 5863** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 5864** 5865** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 5866** error indicating that a string or BLOB is too long to represent. 5867** 5868** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 5869** error indicating that a memory allocation failed. 5870** 5871** ^The sqlite3_result_int() interface sets the return value 5872** of the application-defined function to be the 32-bit signed integer 5873** value given in the 2nd argument. 5874** ^The sqlite3_result_int64() interface sets the return value 5875** of the application-defined function to be the 64-bit signed integer 5876** value given in the 2nd argument. 5877** 5878** ^The sqlite3_result_null() interface sets the return value 5879** of the application-defined function to be NULL. 5880** 5881** ^The sqlite3_result_text(), sqlite3_result_text16(), 5882** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 5883** set the return value of the application-defined function to be 5884** a text string which is represented as UTF-8, UTF-16 native byte order, 5885** UTF-16 little endian, or UTF-16 big endian, respectively. 5886** ^The sqlite3_result_text64() interface sets the return value of an 5887** application-defined function to be a text string in an encoding 5888** specified by the fifth (and last) parameter, which must be one 5889** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 5890** ^SQLite takes the text result from the application from 5891** the 2nd parameter of the sqlite3_result_text* interfaces. 5892** ^If the 3rd parameter to any of the sqlite3_result_text* interfaces 5893** other than sqlite3_result_text64() is negative, then SQLite computes 5894** the string length itself by searching the 2nd parameter for the first 5895** zero character. 5896** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5897** is non-negative, then as many bytes (not characters) of the text 5898** pointed to by the 2nd parameter are taken as the application-defined 5899** function result. If the 3rd parameter is non-negative, then it 5900** must be the byte offset into the string where the NUL terminator would 5901** appear if the string where NUL terminated. If any NUL characters occur 5902** in the string at a byte offset that is less than the value of the 3rd 5903** parameter, then the resulting string will contain embedded NULs and the 5904** result of expressions operating on strings with embedded NULs is undefined. 5905** ^If the 4th parameter to the sqlite3_result_text* interfaces 5906** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 5907** function as the destructor on the text or BLOB result when it has 5908** finished using that result. 5909** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 5910** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 5911** assumes that the text or BLOB result is in constant space and does not 5912** copy the content of the parameter nor call a destructor on the content 5913** when it has finished using that result. 5914** ^If the 4th parameter to the sqlite3_result_text* interfaces 5915** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 5916** then SQLite makes a copy of the result into space obtained 5917** from [sqlite3_malloc()] before it returns. 5918** 5919** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and 5920** sqlite3_result_text16be() routines, and for sqlite3_result_text64() 5921** when the encoding is not UTF8, if the input UTF16 begins with a 5922** byte-order mark (BOM, U+FEFF) then the BOM is removed from the 5923** string and the rest of the string is interpreted according to the 5924** byte-order specified by the BOM. ^The byte-order specified by 5925** the BOM at the beginning of the text overrides the byte-order 5926** specified by the interface procedure. ^So, for example, if 5927** sqlite3_result_text16le() is invoked with text that begins 5928** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the 5929** first two bytes of input are skipped and the remaining input 5930** is interpreted as UTF16BE text. 5931** 5932** ^For UTF16 input text to the sqlite3_result_text16(), 5933** sqlite3_result_text16be(), sqlite3_result_text16le(), and 5934** sqlite3_result_text64() routines, if the text contains invalid 5935** UTF16 characters, the invalid characters might be converted 5936** into the unicode replacement character, U+FFFD. 5937** 5938** ^The sqlite3_result_value() interface sets the result of 5939** the application-defined function to be a copy of the 5940** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 5941** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 5942** so that the [sqlite3_value] specified in the parameter may change or 5943** be deallocated after sqlite3_result_value() returns without harm. 5944** ^A [protected sqlite3_value] object may always be used where an 5945** [unprotected sqlite3_value] object is required, so either 5946** kind of [sqlite3_value] object can be used with this interface. 5947** 5948** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an 5949** SQL NULL value, just like [sqlite3_result_null(C)], except that it 5950** also associates the host-language pointer P or type T with that 5951** NULL value such that the pointer can be retrieved within an 5952** [application-defined SQL function] using [sqlite3_value_pointer()]. 5953** ^If the D parameter is not NULL, then it is a pointer to a destructor 5954** for the P parameter. ^SQLite invokes D with P as its only argument 5955** when SQLite is finished with P. The T parameter should be a static 5956** string and preferably a string literal. The sqlite3_result_pointer() 5957** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5958** 5959** If these routines are called from within the different thread 5960** than the one containing the application-defined function that received 5961** the [sqlite3_context] pointer, the results are undefined. 5962*/ 5963SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 5964SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*, 5965 sqlite3_uint64,void(*)(void*)); 5966SQLITE_API void sqlite3_result_double(sqlite3_context*, double); 5967SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 5968SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 5969SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 5970SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 5971SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 5972SQLITE_API void sqlite3_result_int(sqlite3_context*, int); 5973SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 5974SQLITE_API void sqlite3_result_null(sqlite3_context*); 5975SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 5976SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 5977 void(*)(void*), unsigned char encoding); 5978SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 5979SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 5980SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 5981SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 5982SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 5983SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 5984SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 5985 5986 5987/* 5988** CAPI3REF: Setting The Subtype Of An SQL Function 5989** METHOD: sqlite3_context 5990** 5991** The sqlite3_result_subtype(C,T) function causes the subtype of 5992** the result from the [application-defined SQL function] with 5993** [sqlite3_context] C to be the value T. Only the lower 8 bits 5994** of the subtype T are preserved in current versions of SQLite; 5995** higher order bits are discarded. 5996** The number of subtype bytes preserved by SQLite might increase 5997** in future releases of SQLite. 5998*/ 5999SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int); 6000 6001/* 6002** CAPI3REF: Define New Collating Sequences 6003** METHOD: sqlite3 6004** 6005** ^These functions add, remove, or modify a [collation] associated 6006** with the [database connection] specified as the first argument. 6007** 6008** ^The name of the collation is a UTF-8 string 6009** for sqlite3_create_collation() and sqlite3_create_collation_v2() 6010** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 6011** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 6012** considered to be the same name. 6013** 6014** ^(The third argument (eTextRep) must be one of the constants: 6015** <ul> 6016** <li> [SQLITE_UTF8], 6017** <li> [SQLITE_UTF16LE], 6018** <li> [SQLITE_UTF16BE], 6019** <li> [SQLITE_UTF16], or 6020** <li> [SQLITE_UTF16_ALIGNED]. 6021** </ul>)^ 6022** ^The eTextRep argument determines the encoding of strings passed 6023** to the collating function callback, xCompare. 6024** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 6025** force strings to be UTF16 with native byte order. 6026** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 6027** on an even byte address. 6028** 6029** ^The fourth argument, pArg, is an application data pointer that is passed 6030** through as the first argument to the collating function callback. 6031** 6032** ^The fifth argument, xCompare, is a pointer to the collating function. 6033** ^Multiple collating functions can be registered using the same name but 6034** with different eTextRep parameters and SQLite will use whichever 6035** function requires the least amount of data transformation. 6036** ^If the xCompare argument is NULL then the collating function is 6037** deleted. ^When all collating functions having the same name are deleted, 6038** that collation is no longer usable. 6039** 6040** ^The collating function callback is invoked with a copy of the pArg 6041** application data pointer and with two strings in the encoding specified 6042** by the eTextRep argument. The two integer parameters to the collating 6043** function callback are the length of the two strings, in bytes. The collating 6044** function must return an integer that is negative, zero, or positive 6045** if the first string is less than, equal to, or greater than the second, 6046** respectively. A collating function must always return the same answer 6047** given the same inputs. If two or more collating functions are registered 6048** to the same collation name (using different eTextRep values) then all 6049** must give an equivalent answer when invoked with equivalent strings. 6050** The collating function must obey the following properties for all 6051** strings A, B, and C: 6052** 6053** <ol> 6054** <li> If A==B then B==A. 6055** <li> If A==B and B==C then A==C. 6056** <li> If A<B THEN B>A. 6057** <li> If A<B and B<C then A<C. 6058** </ol> 6059** 6060** If a collating function fails any of the above constraints and that 6061** collating function is registered and used, then the behavior of SQLite 6062** is undefined. 6063** 6064** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 6065** with the addition that the xDestroy callback is invoked on pArg when 6066** the collating function is deleted. 6067** ^Collating functions are deleted when they are overridden by later 6068** calls to the collation creation functions or when the 6069** [database connection] is closed using [sqlite3_close()]. 6070** 6071** ^The xDestroy callback is <u>not</u> called if the 6072** sqlite3_create_collation_v2() function fails. Applications that invoke 6073** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 6074** check the return code and dispose of the application data pointer 6075** themselves rather than expecting SQLite to deal with it for them. 6076** This is different from every other SQLite interface. The inconsistency 6077** is unfortunate but cannot be changed without breaking backwards 6078** compatibility. 6079** 6080** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 6081*/ 6082SQLITE_API int sqlite3_create_collation( 6083 sqlite3*, 6084 const char *zName, 6085 int eTextRep, 6086 void *pArg, 6087 int(*xCompare)(void*,int,const void*,int,const void*) 6088); 6089SQLITE_API int sqlite3_create_collation_v2( 6090 sqlite3*, 6091 const char *zName, 6092 int eTextRep, 6093 void *pArg, 6094 int(*xCompare)(void*,int,const void*,int,const void*), 6095 void(*xDestroy)(void*) 6096); 6097SQLITE_API int sqlite3_create_collation16( 6098 sqlite3*, 6099 const void *zName, 6100 int eTextRep, 6101 void *pArg, 6102 int(*xCompare)(void*,int,const void*,int,const void*) 6103); 6104 6105/* 6106** CAPI3REF: Collation Needed Callbacks 6107** METHOD: sqlite3 6108** 6109** ^To avoid having to register all collation sequences before a database 6110** can be used, a single callback function may be registered with the 6111** [database connection] to be invoked whenever an undefined collation 6112** sequence is required. 6113** 6114** ^If the function is registered using the sqlite3_collation_needed() API, 6115** then it is passed the names of undefined collation sequences as strings 6116** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 6117** the names are passed as UTF-16 in machine native byte order. 6118** ^A call to either function replaces the existing collation-needed callback. 6119** 6120** ^(When the callback is invoked, the first argument passed is a copy 6121** of the second argument to sqlite3_collation_needed() or 6122** sqlite3_collation_needed16(). The second argument is the database 6123** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 6124** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 6125** sequence function required. The fourth parameter is the name of the 6126** required collation sequence.)^ 6127** 6128** The callback function should register the desired collation using 6129** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 6130** [sqlite3_create_collation_v2()]. 6131*/ 6132SQLITE_API int sqlite3_collation_needed( 6133 sqlite3*, 6134 void*, 6135 void(*)(void*,sqlite3*,int eTextRep,const char*) 6136); 6137SQLITE_API int sqlite3_collation_needed16( 6138 sqlite3*, 6139 void*, 6140 void(*)(void*,sqlite3*,int eTextRep,const void*) 6141); 6142 6143#ifdef SQLITE_HAS_CODEC 6144/* 6145** Specify the key for an encrypted database. This routine should be 6146** called right after sqlite3_open(). 6147** 6148** The code to implement this API is not available in the public release 6149** of SQLite. 6150*/ 6151SQLITE_API int sqlite3_key( 6152 sqlite3 *db, /* Database to be rekeyed */ 6153 const void *pKey, int nKey /* The key */ 6154); 6155SQLITE_API int sqlite3_key_v2( 6156 sqlite3 *db, /* Database to be rekeyed */ 6157 const char *zDbName, /* Name of the database */ 6158 const void *pKey, int nKey /* The key */ 6159); 6160 6161/* 6162** Change the key on an open database. If the current database is not 6163** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 6164** database is decrypted. 6165** 6166** The code to implement this API is not available in the public release 6167** of SQLite. 6168*/ 6169SQLITE_API int sqlite3_rekey( 6170 sqlite3 *db, /* Database to be rekeyed */ 6171 const void *pKey, int nKey /* The new key */ 6172); 6173SQLITE_API int sqlite3_rekey_v2( 6174 sqlite3 *db, /* Database to be rekeyed */ 6175 const char *zDbName, /* Name of the database */ 6176 const void *pKey, int nKey /* The new key */ 6177); 6178 6179#endif 6180 6181#ifdef SQLITE_ENABLE_CEROD 6182/* 6183** Specify the activation key for a CEROD database. Unless 6184** activated, none of the CEROD routines will work. 6185*/ 6186SQLITE_API void sqlite3_activate_cerod( 6187 const char *zPassPhrase /* Activation phrase */ 6188); 6189#endif 6190 6191/* 6192** CAPI3REF: Suspend Execution For A Short Time 6193** 6194** The sqlite3_sleep() function causes the current thread to suspend execution 6195** for at least a number of milliseconds specified in its parameter. 6196** 6197** If the operating system does not support sleep requests with 6198** millisecond time resolution, then the time will be rounded up to 6199** the nearest second. The number of milliseconds of sleep actually 6200** requested from the operating system is returned. 6201** 6202** ^SQLite implements this interface by calling the xSleep() 6203** method of the default [sqlite3_vfs] object. If the xSleep() method 6204** of the default VFS is not implemented correctly, or not implemented at 6205** all, then the behavior of sqlite3_sleep() may deviate from the description 6206** in the previous paragraphs. 6207*/ 6208SQLITE_API int sqlite3_sleep(int); 6209 6210/* 6211** CAPI3REF: Name Of The Folder Holding Temporary Files 6212** 6213** ^(If this global variable is made to point to a string which is 6214** the name of a folder (a.k.a. directory), then all temporary files 6215** created by SQLite when using a built-in [sqlite3_vfs | VFS] 6216** will be placed in that directory.)^ ^If this variable 6217** is a NULL pointer, then SQLite performs a search for an appropriate 6218** temporary file directory. 6219** 6220** Applications are strongly discouraged from using this global variable. 6221** It is required to set a temporary folder on Windows Runtime (WinRT). 6222** But for all other platforms, it is highly recommended that applications 6223** neither read nor write this variable. This global variable is a relic 6224** that exists for backwards compatibility of legacy applications and should 6225** be avoided in new projects. 6226** 6227** It is not safe to read or modify this variable in more than one 6228** thread at a time. It is not safe to read or modify this variable 6229** if a [database connection] is being used at the same time in a separate 6230** thread. 6231** It is intended that this variable be set once 6232** as part of process initialization and before any SQLite interface 6233** routines have been called and that this variable remain unchanged 6234** thereafter. 6235** 6236** ^The [temp_store_directory pragma] may modify this variable and cause 6237** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6238** the [temp_store_directory pragma] always assumes that any string 6239** that this variable points to is held in memory obtained from 6240** [sqlite3_malloc] and the pragma may attempt to free that memory 6241** using [sqlite3_free]. 6242** Hence, if this variable is modified directly, either it should be 6243** made NULL or made to point to memory obtained from [sqlite3_malloc] 6244** or else the use of the [temp_store_directory pragma] should be avoided. 6245** Except when requested by the [temp_store_directory pragma], SQLite 6246** does not free the memory that sqlite3_temp_directory points to. If 6247** the application wants that memory to be freed, it must do 6248** so itself, taking care to only do so after all [database connection] 6249** objects have been destroyed. 6250** 6251** <b>Note to Windows Runtime users:</b> The temporary directory must be set 6252** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 6253** features that require the use of temporary files may fail. Here is an 6254** example of how to do this using C++ with the Windows Runtime: 6255** 6256** <blockquote><pre> 6257** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 6258** TemporaryFolder->Path->Data(); 6259** char zPathBuf[MAX_PATH + 1]; 6260** memset(zPathBuf, 0, sizeof(zPathBuf)); 6261** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 6262** NULL, NULL); 6263** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 6264** </pre></blockquote> 6265*/ 6266SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; 6267 6268/* 6269** CAPI3REF: Name Of The Folder Holding Database Files 6270** 6271** ^(If this global variable is made to point to a string which is 6272** the name of a folder (a.k.a. directory), then all database files 6273** specified with a relative pathname and created or accessed by 6274** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 6275** to be relative to that directory.)^ ^If this variable is a NULL 6276** pointer, then SQLite assumes that all database files specified 6277** with a relative pathname are relative to the current directory 6278** for the process. Only the windows VFS makes use of this global 6279** variable; it is ignored by the unix VFS. 6280** 6281** Changing the value of this variable while a database connection is 6282** open can result in a corrupt database. 6283** 6284** It is not safe to read or modify this variable in more than one 6285** thread at a time. It is not safe to read or modify this variable 6286** if a [database connection] is being used at the same time in a separate 6287** thread. 6288** It is intended that this variable be set once 6289** as part of process initialization and before any SQLite interface 6290** routines have been called and that this variable remain unchanged 6291** thereafter. 6292** 6293** ^The [data_store_directory pragma] may modify this variable and cause 6294** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 6295** the [data_store_directory pragma] always assumes that any string 6296** that this variable points to is held in memory obtained from 6297** [sqlite3_malloc] and the pragma may attempt to free that memory 6298** using [sqlite3_free]. 6299** Hence, if this variable is modified directly, either it should be 6300** made NULL or made to point to memory obtained from [sqlite3_malloc] 6301** or else the use of the [data_store_directory pragma] should be avoided. 6302*/ 6303SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory; 6304 6305/* 6306** CAPI3REF: Win32 Specific Interface 6307** 6308** These interfaces are available only on Windows. The 6309** [sqlite3_win32_set_directory] interface is used to set the value associated 6310** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to 6311** zValue, depending on the value of the type parameter. The zValue parameter 6312** should be NULL to cause the previous value to be freed via [sqlite3_free]; 6313** a non-NULL value will be copied into memory obtained from [sqlite3_malloc] 6314** prior to being used. The [sqlite3_win32_set_directory] interface returns 6315** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported, 6316** or [SQLITE_NOMEM] if memory could not be allocated. The value of the 6317** [sqlite3_data_directory] variable is intended to act as a replacement for 6318** the current directory on the sub-platforms of Win32 where that concept is 6319** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and 6320** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the 6321** sqlite3_win32_set_directory interface except the string parameter must be 6322** UTF-8 or UTF-16, respectively. 6323*/ 6324SQLITE_API int sqlite3_win32_set_directory( 6325 unsigned long type, /* Identifier for directory being set or reset */ 6326 void *zValue /* New value for directory being set or reset */ 6327); 6328SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue); 6329SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue); 6330 6331/* 6332** CAPI3REF: Win32 Directory Types 6333** 6334** These macros are only available on Windows. They define the allowed values 6335** for the type argument to the [sqlite3_win32_set_directory] interface. 6336*/ 6337#define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1 6338#define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2 6339 6340/* 6341** CAPI3REF: Test For Auto-Commit Mode 6342** KEYWORDS: {autocommit mode} 6343** METHOD: sqlite3 6344** 6345** ^The sqlite3_get_autocommit() interface returns non-zero or 6346** zero if the given database connection is or is not in autocommit mode, 6347** respectively. ^Autocommit mode is on by default. 6348** ^Autocommit mode is disabled by a [BEGIN] statement. 6349** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 6350** 6351** If certain kinds of errors occur on a statement within a multi-statement 6352** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 6353** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 6354** transaction might be rolled back automatically. The only way to 6355** find out whether SQLite automatically rolled back the transaction after 6356** an error is to use this function. 6357** 6358** If another thread changes the autocommit status of the database 6359** connection while this routine is running, then the return value 6360** is undefined. 6361*/ 6362SQLITE_API int sqlite3_get_autocommit(sqlite3*); 6363 6364/* 6365** CAPI3REF: Find The Database Handle Of A Prepared Statement 6366** METHOD: sqlite3_stmt 6367** 6368** ^The sqlite3_db_handle interface returns the [database connection] handle 6369** to which a [prepared statement] belongs. ^The [database connection] 6370** returned by sqlite3_db_handle is the same [database connection] 6371** that was the first argument 6372** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 6373** create the statement in the first place. 6374*/ 6375SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 6376 6377/* 6378** CAPI3REF: Return The Schema Name For A Database Connection 6379** METHOD: sqlite3 6380** 6381** ^The sqlite3_db_name(D,N) interface returns a pointer to the schema name 6382** for the N-th database on database connection D, or a NULL pointer of N is 6383** out of range. An N value of 0 means the main database file. An N of 1 is 6384** the "temp" schema. Larger values of N correspond to various ATTACH-ed 6385** databases. 6386** 6387** Space to hold the string that is returned by sqlite3_db_name() is managed 6388** by SQLite itself. The string might be deallocated by any operation that 6389** changes the schema, including [ATTACH] or [DETACH] or calls to 6390** [sqlite3_serialize()] or [sqlite3_deserialize()], even operations that 6391** occur on a different thread. Applications that need to 6392** remember the string long-term should make their own copy. Applications that 6393** are accessing the same database connection simultaneously on multiple 6394** threads should mutex-protect calls to this API and should make their own 6395** private copy of the result prior to releasing the mutex. 6396*/ 6397SQLITE_API const char *sqlite3_db_name(sqlite3 *db, int N); 6398 6399/* 6400** CAPI3REF: Return The Filename For A Database Connection 6401** METHOD: sqlite3 6402** 6403** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename 6404** associated with database N of connection D. 6405** ^If there is no attached database N on the database 6406** connection D, or if database N is a temporary or in-memory database, then 6407** this function will return either a NULL pointer or an empty string. 6408** 6409** ^The string value returned by this routine is owned and managed by 6410** the database connection. ^The value will be valid until the database N 6411** is [DETACH]-ed or until the database connection closes. 6412** 6413** ^The filename returned by this function is the output of the 6414** xFullPathname method of the [VFS]. ^In other words, the filename 6415** will be an absolute pathname, even if the filename used 6416** to open the database originally was a URI or relative pathname. 6417** 6418** If the filename pointer returned by this routine is not NULL, then it 6419** can be used as the filename input parameter to these routines: 6420** <ul> 6421** <li> [sqlite3_uri_parameter()] 6422** <li> [sqlite3_uri_boolean()] 6423** <li> [sqlite3_uri_int64()] 6424** <li> [sqlite3_filename_database()] 6425** <li> [sqlite3_filename_journal()] 6426** <li> [sqlite3_filename_wal()] 6427** </ul> 6428*/ 6429SQLITE_API sqlite3_filename sqlite3_db_filename(sqlite3 *db, const char *zDbName); 6430 6431/* 6432** CAPI3REF: Determine if a database is read-only 6433** METHOD: sqlite3 6434** 6435** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 6436** of connection D is read-only, 0 if it is read/write, or -1 if N is not 6437** the name of a database on connection D. 6438*/ 6439SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 6440 6441/* 6442** CAPI3REF: Determine the transaction state of a database 6443** METHOD: sqlite3 6444** 6445** ^The sqlite3_txn_state(D,S) interface returns the current 6446** [transaction state] of schema S in database connection D. ^If S is NULL, 6447** then the highest transaction state of any schema on database connection D 6448** is returned. Transaction states are (in order of lowest to highest): 6449** <ol> 6450** <li value="0"> SQLITE_TXN_NONE 6451** <li value="1"> SQLITE_TXN_READ 6452** <li value="2"> SQLITE_TXN_WRITE 6453** </ol> 6454** ^If the S argument to sqlite3_txn_state(D,S) is not the name of 6455** a valid schema, then -1 is returned. 6456*/ 6457SQLITE_API int sqlite3_txn_state(sqlite3*,const char *zSchema); 6458 6459/* 6460** CAPI3REF: Allowed return values from [sqlite3_txn_state()] 6461** KEYWORDS: {transaction state} 6462** 6463** These constants define the current transaction state of a database file. 6464** ^The [sqlite3_txn_state(D,S)] interface returns one of these 6465** constants in order to describe the transaction state of schema S 6466** in [database connection] D. 6467** 6468** <dl> 6469** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt> 6470** <dd>The SQLITE_TXN_NONE state means that no transaction is currently 6471** pending.</dd> 6472** 6473** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt> 6474** <dd>The SQLITE_TXN_READ state means that the database is currently 6475** in a read transaction. Content has been read from the database file 6476** but nothing in the database file has changed. The transaction state 6477** will advanced to SQLITE_TXN_WRITE if any changes occur and there are 6478** no other conflicting concurrent write transactions. The transaction 6479** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or 6480** [COMMIT].</dd> 6481** 6482** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt> 6483** <dd>The SQLITE_TXN_WRITE state means that the database is currently 6484** in a write transaction. Content has been written to the database file 6485** but has not yet committed. The transaction state will change to 6486** to SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd> 6487*/ 6488#define SQLITE_TXN_NONE 0 6489#define SQLITE_TXN_READ 1 6490#define SQLITE_TXN_WRITE 2 6491 6492/* 6493** CAPI3REF: Find the next prepared statement 6494** METHOD: sqlite3 6495** 6496** ^This interface returns a pointer to the next [prepared statement] after 6497** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 6498** then this interface returns a pointer to the first prepared statement 6499** associated with the database connection pDb. ^If no prepared statement 6500** satisfies the conditions of this routine, it returns NULL. 6501** 6502** The [database connection] pointer D in a call to 6503** [sqlite3_next_stmt(D,S)] must refer to an open database 6504** connection and in particular must not be a NULL pointer. 6505*/ 6506SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 6507 6508/* 6509** CAPI3REF: Commit And Rollback Notification Callbacks 6510** METHOD: sqlite3 6511** 6512** ^The sqlite3_commit_hook() interface registers a callback 6513** function to be invoked whenever a transaction is [COMMIT | committed]. 6514** ^Any callback set by a previous call to sqlite3_commit_hook() 6515** for the same database connection is overridden. 6516** ^The sqlite3_rollback_hook() interface registers a callback 6517** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 6518** ^Any callback set by a previous call to sqlite3_rollback_hook() 6519** for the same database connection is overridden. 6520** ^The pArg argument is passed through to the callback. 6521** ^If the callback on a commit hook function returns non-zero, 6522** then the commit is converted into a rollback. 6523** 6524** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 6525** return the P argument from the previous call of the same function 6526** on the same [database connection] D, or NULL for 6527** the first call for each function on D. 6528** 6529** The commit and rollback hook callbacks are not reentrant. 6530** The callback implementation must not do anything that will modify 6531** the database connection that invoked the callback. Any actions 6532** to modify the database connection must be deferred until after the 6533** completion of the [sqlite3_step()] call that triggered the commit 6534** or rollback hook in the first place. 6535** Note that running any other SQL statements, including SELECT statements, 6536** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 6537** the database connections for the meaning of "modify" in this paragraph. 6538** 6539** ^Registering a NULL function disables the callback. 6540** 6541** ^When the commit hook callback routine returns zero, the [COMMIT] 6542** operation is allowed to continue normally. ^If the commit hook 6543** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 6544** ^The rollback hook is invoked on a rollback that results from a commit 6545** hook returning non-zero, just as it would be with any other rollback. 6546** 6547** ^For the purposes of this API, a transaction is said to have been 6548** rolled back if an explicit "ROLLBACK" statement is executed, or 6549** an error or constraint causes an implicit rollback to occur. 6550** ^The rollback callback is not invoked if a transaction is 6551** automatically rolled back because the database connection is closed. 6552** 6553** See also the [sqlite3_update_hook()] interface. 6554*/ 6555SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 6556SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 6557 6558/* 6559** CAPI3REF: Autovacuum Compaction Amount Callback 6560** METHOD: sqlite3 6561** 6562** ^The sqlite3_autovacuum_pages(D,C,P,X) interface registers a callback 6563** function C that is invoked prior to each autovacuum of the database 6564** file. ^The callback is passed a copy of the generic data pointer (P), 6565** the schema-name of the attached database that is being autovacuumed, 6566** the size of the database file in pages, the number of free pages, 6567** and the number of bytes per page, respectively. The callback should 6568** return the number of free pages that should be removed by the 6569** autovacuum. ^If the callback returns zero, then no autovacuum happens. 6570** ^If the value returned is greater than or equal to the number of 6571** free pages, then a complete autovacuum happens. 6572** 6573** <p>^If there are multiple ATTACH-ed database files that are being 6574** modified as part of a transaction commit, then the autovacuum pages 6575** callback is invoked separately for each file. 6576** 6577** <p><b>The callback is not reentrant.</b> The callback function should 6578** not attempt to invoke any other SQLite interface. If it does, bad 6579** things may happen, including segmentation faults and corrupt database 6580** files. The callback function should be a simple function that 6581** does some arithmetic on its input parameters and returns a result. 6582** 6583** ^The X parameter to sqlite3_autovacuum_pages(D,C,P,X) is an optional 6584** destructor for the P parameter. ^If X is not NULL, then X(P) is 6585** invoked whenever the database connection closes or when the callback 6586** is overwritten by another invocation of sqlite3_autovacuum_pages(). 6587** 6588** <p>^There is only one autovacuum pages callback per database connection. 6589** ^Each call to the sqlite3_autovacuum_pages() interface overrides all 6590** previous invocations for that database connection. ^If the callback 6591** argument (C) to sqlite3_autovacuum_pages(D,C,P,X) is a NULL pointer, 6592** then the autovacuum steps callback is cancelled. The return value 6593** from sqlite3_autovacuum_pages() is normally SQLITE_OK, but might 6594** be some other error code if something goes wrong. The current 6595** implementation will only return SQLITE_OK or SQLITE_MISUSE, but other 6596** return codes might be added in future releases. 6597** 6598** <p>If no autovacuum pages callback is specified (the usual case) or 6599** a NULL pointer is provided for the callback, 6600** then the default behavior is to vacuum all free pages. So, in other 6601** words, the default behavior is the same as if the callback function 6602** were something like this: 6603** 6604** <blockquote><pre> 6605** unsigned int demonstration_autovac_pages_callback( 6606** void *pClientData, 6607** const char *zSchema, 6608** unsigned int nDbPage, 6609** unsigned int nFreePage, 6610** unsigned int nBytePerPage 6611** ){ 6612** return nFreePage; 6613** } 6614** </pre></blockquote> 6615*/ 6616SQLITE_API int sqlite3_autovacuum_pages( 6617 sqlite3 *db, 6618 unsigned int(*)(void*,const char*,unsigned int,unsigned int,unsigned int), 6619 void*, 6620 void(*)(void*) 6621); 6622 6623 6624/* 6625** CAPI3REF: Data Change Notification Callbacks 6626** METHOD: sqlite3 6627** 6628** ^The sqlite3_update_hook() interface registers a callback function 6629** with the [database connection] identified by the first argument 6630** to be invoked whenever a row is updated, inserted or deleted in 6631** a [rowid table]. 6632** ^Any callback set by a previous call to this function 6633** for the same database connection is overridden. 6634** 6635** ^The second argument is a pointer to the function to invoke when a 6636** row is updated, inserted or deleted in a rowid table. 6637** ^The first argument to the callback is a copy of the third argument 6638** to sqlite3_update_hook(). 6639** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 6640** or [SQLITE_UPDATE], depending on the operation that caused the callback 6641** to be invoked. 6642** ^The third and fourth arguments to the callback contain pointers to the 6643** database and table name containing the affected row. 6644** ^The final callback parameter is the [rowid] of the row. 6645** ^In the case of an update, this is the [rowid] after the update takes place. 6646** 6647** ^(The update hook is not invoked when internal system tables are 6648** modified (i.e. sqlite_sequence).)^ 6649** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 6650** 6651** ^In the current implementation, the update hook 6652** is not invoked when conflicting rows are deleted because of an 6653** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 6654** invoked when rows are deleted using the [truncate optimization]. 6655** The exceptions defined in this paragraph might change in a future 6656** release of SQLite. 6657** 6658** The update hook implementation must not do anything that will modify 6659** the database connection that invoked the update hook. Any actions 6660** to modify the database connection must be deferred until after the 6661** completion of the [sqlite3_step()] call that triggered the update hook. 6662** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 6663** database connections for the meaning of "modify" in this paragraph. 6664** 6665** ^The sqlite3_update_hook(D,C,P) function 6666** returns the P argument from the previous call 6667** on the same [database connection] D, or NULL for 6668** the first call on D. 6669** 6670** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 6671** and [sqlite3_preupdate_hook()] interfaces. 6672*/ 6673SQLITE_API void *sqlite3_update_hook( 6674 sqlite3*, 6675 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 6676 void* 6677); 6678 6679/* 6680** CAPI3REF: Enable Or Disable Shared Pager Cache 6681** 6682** ^(This routine enables or disables the sharing of the database cache 6683** and schema data structures between [database connection | connections] 6684** to the same database. Sharing is enabled if the argument is true 6685** and disabled if the argument is false.)^ 6686** 6687** This interface is omitted if SQLite is compiled with 6688** [-DSQLITE_OMIT_SHARED_CACHE]. The [-DSQLITE_OMIT_SHARED_CACHE] 6689** compile-time option is recommended because the 6690** [use of shared cache mode is discouraged]. 6691** 6692** ^Cache sharing is enabled and disabled for an entire process. 6693** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 6694** In prior versions of SQLite, 6695** sharing was enabled or disabled for each thread separately. 6696** 6697** ^(The cache sharing mode set by this interface effects all subsequent 6698** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 6699** Existing database connections continue to use the sharing mode 6700** that was in effect at the time they were opened.)^ 6701** 6702** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 6703** successfully. An [error code] is returned otherwise.)^ 6704** 6705** ^Shared cache is disabled by default. It is recommended that it stay 6706** that way. In other words, do not use this routine. This interface 6707** continues to be provided for historical compatibility, but its use is 6708** discouraged. Any use of shared cache is discouraged. If shared cache 6709** must be used, it is recommended that shared cache only be enabled for 6710** individual database connections using the [sqlite3_open_v2()] interface 6711** with the [SQLITE_OPEN_SHAREDCACHE] flag. 6712** 6713** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 6714** and will always return SQLITE_MISUSE. On those systems, 6715** shared cache mode should be enabled per-database connection via 6716** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 6717** 6718** This interface is threadsafe on processors where writing a 6719** 32-bit integer is atomic. 6720** 6721** See Also: [SQLite Shared-Cache Mode] 6722*/ 6723SQLITE_API int sqlite3_enable_shared_cache(int); 6724 6725/* 6726** CAPI3REF: Attempt To Free Heap Memory 6727** 6728** ^The sqlite3_release_memory() interface attempts to free N bytes 6729** of heap memory by deallocating non-essential memory allocations 6730** held by the database library. Memory used to cache database 6731** pages to improve performance is an example of non-essential memory. 6732** ^sqlite3_release_memory() returns the number of bytes actually freed, 6733** which might be more or less than the amount requested. 6734** ^The sqlite3_release_memory() routine is a no-op returning zero 6735** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 6736** 6737** See also: [sqlite3_db_release_memory()] 6738*/ 6739SQLITE_API int sqlite3_release_memory(int); 6740 6741/* 6742** CAPI3REF: Free Memory Used By A Database Connection 6743** METHOD: sqlite3 6744** 6745** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 6746** memory as possible from database connection D. Unlike the 6747** [sqlite3_release_memory()] interface, this interface is in effect even 6748** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 6749** omitted. 6750** 6751** See also: [sqlite3_release_memory()] 6752*/ 6753SQLITE_API int sqlite3_db_release_memory(sqlite3*); 6754 6755/* 6756** CAPI3REF: Impose A Limit On Heap Size 6757** 6758** These interfaces impose limits on the amount of heap memory that will be 6759** by all database connections within a single process. 6760** 6761** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 6762** soft limit on the amount of heap memory that may be allocated by SQLite. 6763** ^SQLite strives to keep heap memory utilization below the soft heap 6764** limit by reducing the number of pages held in the page cache 6765** as heap memory usages approaches the limit. 6766** ^The soft heap limit is "soft" because even though SQLite strives to stay 6767** below the limit, it will exceed the limit rather than generate 6768** an [SQLITE_NOMEM] error. In other words, the soft heap limit 6769** is advisory only. 6770** 6771** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of 6772** N bytes on the amount of memory that will be allocated. ^The 6773** sqlite3_hard_heap_limit64(N) interface is similar to 6774** sqlite3_soft_heap_limit64(N) except that memory allocations will fail 6775** when the hard heap limit is reached. 6776** 6777** ^The return value from both sqlite3_soft_heap_limit64() and 6778** sqlite3_hard_heap_limit64() is the size of 6779** the heap limit prior to the call, or negative in the case of an 6780** error. ^If the argument N is negative 6781** then no change is made to the heap limit. Hence, the current 6782** size of heap limits can be determined by invoking 6783** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1). 6784** 6785** ^Setting the heap limits to zero disables the heap limiter mechanism. 6786** 6787** ^The soft heap limit may not be greater than the hard heap limit. 6788** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N) 6789** is invoked with a value of N that is greater than the hard heap limit, 6790** the soft heap limit is set to the value of the hard heap limit. 6791** ^The soft heap limit is automatically enabled whenever the hard heap 6792** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and 6793** the soft heap limit is outside the range of 1..N, then the soft heap 6794** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the 6795** hard heap limit is enabled makes the soft heap limit equal to the 6796** hard heap limit. 6797** 6798** The memory allocation limits can also be adjusted using 6799** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit]. 6800** 6801** ^(The heap limits are not enforced in the current implementation 6802** if one or more of following conditions are true: 6803** 6804** <ul> 6805** <li> The limit value is set to zero. 6806** <li> Memory accounting is disabled using a combination of the 6807** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 6808** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 6809** <li> An alternative page cache implementation is specified using 6810** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 6811** <li> The page cache allocates from its own memory pool supplied 6812** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 6813** from the heap. 6814** </ul>)^ 6815** 6816** The circumstances under which SQLite will enforce the heap limits may 6817** changes in future releases of SQLite. 6818*/ 6819SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 6820SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N); 6821 6822/* 6823** CAPI3REF: Deprecated Soft Heap Limit Interface 6824** DEPRECATED 6825** 6826** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 6827** interface. This routine is provided for historical compatibility 6828** only. All new applications should use the 6829** [sqlite3_soft_heap_limit64()] interface rather than this one. 6830*/ 6831SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 6832 6833 6834/* 6835** CAPI3REF: Extract Metadata About A Column Of A Table 6836** METHOD: sqlite3 6837** 6838** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 6839** information about column C of table T in database D 6840** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 6841** interface returns SQLITE_OK and fills in the non-NULL pointers in 6842** the final five arguments with appropriate values if the specified 6843** column exists. ^The sqlite3_table_column_metadata() interface returns 6844** SQLITE_ERROR if the specified column does not exist. 6845** ^If the column-name parameter to sqlite3_table_column_metadata() is a 6846** NULL pointer, then this routine simply checks for the existence of the 6847** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 6848** does not. If the table name parameter T in a call to 6849** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is 6850** undefined behavior. 6851** 6852** ^The column is identified by the second, third and fourth parameters to 6853** this function. ^(The second parameter is either the name of the database 6854** (i.e. "main", "temp", or an attached database) containing the specified 6855** table or NULL.)^ ^If it is NULL, then all attached databases are searched 6856** for the table using the same algorithm used by the database engine to 6857** resolve unqualified table references. 6858** 6859** ^The third and fourth parameters to this function are the table and column 6860** name of the desired column, respectively. 6861** 6862** ^Metadata is returned by writing to the memory locations passed as the 5th 6863** and subsequent parameters to this function. ^Any of these arguments may be 6864** NULL, in which case the corresponding element of metadata is omitted. 6865** 6866** ^(<blockquote> 6867** <table border="1"> 6868** <tr><th> Parameter <th> Output<br>Type <th> Description 6869** 6870** <tr><td> 5th <td> const char* <td> Data type 6871** <tr><td> 6th <td> const char* <td> Name of default collation sequence 6872** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 6873** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 6874** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 6875** </table> 6876** </blockquote>)^ 6877** 6878** ^The memory pointed to by the character pointers returned for the 6879** declaration type and collation sequence is valid until the next 6880** call to any SQLite API function. 6881** 6882** ^If the specified table is actually a view, an [error code] is returned. 6883** 6884** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 6885** is not a [WITHOUT ROWID] table and an 6886** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 6887** parameters are set for the explicitly declared column. ^(If there is no 6888** [INTEGER PRIMARY KEY] column, then the outputs 6889** for the [rowid] are set as follows: 6890** 6891** <pre> 6892** data type: "INTEGER" 6893** collation sequence: "BINARY" 6894** not null: 0 6895** primary key: 1 6896** auto increment: 0 6897** </pre>)^ 6898** 6899** ^This function causes all database schemas to be read from disk and 6900** parsed, if that has not already been done, and returns an error if 6901** any errors are encountered while loading the schema. 6902*/ 6903SQLITE_API int sqlite3_table_column_metadata( 6904 sqlite3 *db, /* Connection handle */ 6905 const char *zDbName, /* Database name or NULL */ 6906 const char *zTableName, /* Table name */ 6907 const char *zColumnName, /* Column name */ 6908 char const **pzDataType, /* OUTPUT: Declared data type */ 6909 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 6910 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 6911 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 6912 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 6913); 6914 6915/* 6916** CAPI3REF: Load An Extension 6917** METHOD: sqlite3 6918** 6919** ^This interface loads an SQLite extension library from the named file. 6920** 6921** ^The sqlite3_load_extension() interface attempts to load an 6922** [SQLite extension] library contained in the file zFile. If 6923** the file cannot be loaded directly, attempts are made to load 6924** with various operating-system specific extensions added. 6925** So for example, if "samplelib" cannot be loaded, then names like 6926** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 6927** be tried also. 6928** 6929** ^The entry point is zProc. 6930** ^(zProc may be 0, in which case SQLite will try to come up with an 6931** entry point name on its own. It first tries "sqlite3_extension_init". 6932** If that does not work, it constructs a name "sqlite3_X_init" where the 6933** X is consists of the lower-case equivalent of all ASCII alphabetic 6934** characters in the filename from the last "/" to the first following 6935** "." and omitting any initial "lib".)^ 6936** ^The sqlite3_load_extension() interface returns 6937** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 6938** ^If an error occurs and pzErrMsg is not 0, then the 6939** [sqlite3_load_extension()] interface shall attempt to 6940** fill *pzErrMsg with error message text stored in memory 6941** obtained from [sqlite3_malloc()]. The calling function 6942** should free this memory by calling [sqlite3_free()]. 6943** 6944** ^Extension loading must be enabled using 6945** [sqlite3_enable_load_extension()] or 6946** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 6947** prior to calling this API, 6948** otherwise an error will be returned. 6949** 6950** <b>Security warning:</b> It is recommended that the 6951** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 6952** interface. The use of the [sqlite3_enable_load_extension()] interface 6953** should be avoided. This will keep the SQL function [load_extension()] 6954** disabled and prevent SQL injections from giving attackers 6955** access to extension loading capabilities. 6956** 6957** See also the [load_extension() SQL function]. 6958*/ 6959SQLITE_API int sqlite3_load_extension( 6960 sqlite3 *db, /* Load the extension into this database connection */ 6961 const char *zFile, /* Name of the shared library containing extension */ 6962 const char *zProc, /* Entry point. Derived from zFile if 0 */ 6963 char **pzErrMsg /* Put error message here if not 0 */ 6964); 6965 6966/* 6967** CAPI3REF: Enable Or Disable Extension Loading 6968** METHOD: sqlite3 6969** 6970** ^So as not to open security holes in older applications that are 6971** unprepared to deal with [extension loading], and as a means of disabling 6972** [extension loading] while evaluating user-entered SQL, the following API 6973** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 6974** 6975** ^Extension loading is off by default. 6976** ^Call the sqlite3_enable_load_extension() routine with onoff==1 6977** to turn extension loading on and call it with onoff==0 to turn 6978** it back off again. 6979** 6980** ^This interface enables or disables both the C-API 6981** [sqlite3_load_extension()] and the SQL function [load_extension()]. 6982** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 6983** to enable or disable only the C-API.)^ 6984** 6985** <b>Security warning:</b> It is recommended that extension loading 6986** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 6987** rather than this interface, so the [load_extension()] SQL function 6988** remains disabled. This will prevent SQL injections from giving attackers 6989** access to extension loading capabilities. 6990*/ 6991SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 6992 6993/* 6994** CAPI3REF: Automatically Load Statically Linked Extensions 6995** 6996** ^This interface causes the xEntryPoint() function to be invoked for 6997** each new [database connection] that is created. The idea here is that 6998** xEntryPoint() is the entry point for a statically linked [SQLite extension] 6999** that is to be automatically loaded into all new database connections. 7000** 7001** ^(Even though the function prototype shows that xEntryPoint() takes 7002** no arguments and returns void, SQLite invokes xEntryPoint() with three 7003** arguments and expects an integer result as if the signature of the 7004** entry point where as follows: 7005** 7006** <blockquote><pre> 7007** int xEntryPoint( 7008** sqlite3 *db, 7009** const char **pzErrMsg, 7010** const struct sqlite3_api_routines *pThunk 7011** ); 7012** </pre></blockquote>)^ 7013** 7014** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 7015** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 7016** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 7017** is NULL before calling the xEntryPoint(). ^SQLite will invoke 7018** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 7019** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 7020** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 7021** 7022** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 7023** on the list of automatic extensions is a harmless no-op. ^No entry point 7024** will be called more than once for each database connection that is opened. 7025** 7026** See also: [sqlite3_reset_auto_extension()] 7027** and [sqlite3_cancel_auto_extension()] 7028*/ 7029SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void)); 7030 7031/* 7032** CAPI3REF: Cancel Automatic Extension Loading 7033** 7034** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 7035** initialization routine X that was registered using a prior call to 7036** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 7037** routine returns 1 if initialization routine X was successfully 7038** unregistered and it returns 0 if X was not on the list of initialization 7039** routines. 7040*/ 7041SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 7042 7043/* 7044** CAPI3REF: Reset Automatic Extension Loading 7045** 7046** ^This interface disables all automatic extensions previously 7047** registered using [sqlite3_auto_extension()]. 7048*/ 7049SQLITE_API void sqlite3_reset_auto_extension(void); 7050 7051/* 7052** The interface to the virtual-table mechanism is currently considered 7053** to be experimental. The interface might change in incompatible ways. 7054** If this is a problem for you, do not use the interface at this time. 7055** 7056** When the virtual-table mechanism stabilizes, we will declare the 7057** interface fixed, support it indefinitely, and remove this comment. 7058*/ 7059 7060/* 7061** Structures used by the virtual table interface 7062*/ 7063typedef struct sqlite3_vtab sqlite3_vtab; 7064typedef struct sqlite3_index_info sqlite3_index_info; 7065typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 7066typedef struct sqlite3_module sqlite3_module; 7067 7068/* 7069** CAPI3REF: Virtual Table Object 7070** KEYWORDS: sqlite3_module {virtual table module} 7071** 7072** This structure, sometimes called a "virtual table module", 7073** defines the implementation of a [virtual table]. 7074** This structure consists mostly of methods for the module. 7075** 7076** ^A virtual table module is created by filling in a persistent 7077** instance of this structure and passing a pointer to that instance 7078** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 7079** ^The registration remains valid until it is replaced by a different 7080** module or until the [database connection] closes. The content 7081** of this structure must not change while it is registered with 7082** any database connection. 7083*/ 7084struct sqlite3_module { 7085 int iVersion; 7086 int (*xCreate)(sqlite3*, void *pAux, 7087 int argc, const char *const*argv, 7088 sqlite3_vtab **ppVTab, char**); 7089 int (*xConnect)(sqlite3*, void *pAux, 7090 int argc, const char *const*argv, 7091 sqlite3_vtab **ppVTab, char**); 7092 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 7093 int (*xDisconnect)(sqlite3_vtab *pVTab); 7094 int (*xDestroy)(sqlite3_vtab *pVTab); 7095 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 7096 int (*xClose)(sqlite3_vtab_cursor*); 7097 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 7098 int argc, sqlite3_value **argv); 7099 int (*xNext)(sqlite3_vtab_cursor*); 7100 int (*xEof)(sqlite3_vtab_cursor*); 7101 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 7102 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 7103 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 7104 int (*xBegin)(sqlite3_vtab *pVTab); 7105 int (*xSync)(sqlite3_vtab *pVTab); 7106 int (*xCommit)(sqlite3_vtab *pVTab); 7107 int (*xRollback)(sqlite3_vtab *pVTab); 7108 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 7109 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 7110 void **ppArg); 7111 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 7112 /* The methods above are in version 1 of the sqlite_module object. Those 7113 ** below are for version 2 and greater. */ 7114 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 7115 int (*xRelease)(sqlite3_vtab *pVTab, int); 7116 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 7117 /* The methods above are in versions 1 and 2 of the sqlite_module object. 7118 ** Those below are for version 3 and greater. */ 7119 int (*xShadowName)(const char*); 7120}; 7121 7122/* 7123** CAPI3REF: Virtual Table Indexing Information 7124** KEYWORDS: sqlite3_index_info 7125** 7126** The sqlite3_index_info structure and its substructures is used as part 7127** of the [virtual table] interface to 7128** pass information into and receive the reply from the [xBestIndex] 7129** method of a [virtual table module]. The fields under **Inputs** are the 7130** inputs to xBestIndex and are read-only. xBestIndex inserts its 7131** results into the **Outputs** fields. 7132** 7133** ^(The aConstraint[] array records WHERE clause constraints of the form: 7134** 7135** <blockquote>column OP expr</blockquote> 7136** 7137** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 7138** stored in aConstraint[].op using one of the 7139** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 7140** ^(The index of the column is stored in 7141** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 7142** expr on the right-hand side can be evaluated (and thus the constraint 7143** is usable) and false if it cannot.)^ 7144** 7145** ^The optimizer automatically inverts terms of the form "expr OP column" 7146** and makes other simplifications to the WHERE clause in an attempt to 7147** get as many WHERE clause terms into the form shown above as possible. 7148** ^The aConstraint[] array only reports WHERE clause terms that are 7149** relevant to the particular virtual table being queried. 7150** 7151** ^Information about the ORDER BY clause is stored in aOrderBy[]. 7152** ^Each term of aOrderBy records a column of the ORDER BY clause. 7153** 7154** The colUsed field indicates which columns of the virtual table may be 7155** required by the current scan. Virtual table columns are numbered from 7156** zero in the order in which they appear within the CREATE TABLE statement 7157** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 7158** the corresponding bit is set within the colUsed mask if the column may be 7159** required by SQLite. If the table has at least 64 columns and any column 7160** to the right of the first 63 is required, then bit 63 of colUsed is also 7161** set. In other words, column iCol may be required if the expression 7162** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 7163** non-zero. 7164** 7165** The [xBestIndex] method must fill aConstraintUsage[] with information 7166** about what parameters to pass to xFilter. ^If argvIndex>0 then 7167** the right-hand side of the corresponding aConstraint[] is evaluated 7168** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 7169** is true, then the constraint is assumed to be fully handled by the 7170** virtual table and might not be checked again by the byte code.)^ ^(The 7171** aConstraintUsage[].omit flag is an optimization hint. When the omit flag 7172** is left in its default setting of false, the constraint will always be 7173** checked separately in byte code. If the omit flag is change to true, then 7174** the constraint may or may not be checked in byte code. In other words, 7175** when the omit flag is true there is no guarantee that the constraint will 7176** not be checked again using byte code.)^ 7177** 7178** ^The idxNum and idxPtr values are recorded and passed into the 7179** [xFilter] method. 7180** ^[sqlite3_free()] is used to free idxPtr if and only if 7181** needToFreeIdxPtr is true. 7182** 7183** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 7184** the correct order to satisfy the ORDER BY clause so that no separate 7185** sorting step is required. 7186** 7187** ^The estimatedCost value is an estimate of the cost of a particular 7188** strategy. A cost of N indicates that the cost of the strategy is similar 7189** to a linear scan of an SQLite table with N rows. A cost of log(N) 7190** indicates that the expense of the operation is similar to that of a 7191** binary search on a unique indexed field of an SQLite table with N rows. 7192** 7193** ^The estimatedRows value is an estimate of the number of rows that 7194** will be returned by the strategy. 7195** 7196** The xBestIndex method may optionally populate the idxFlags field with a 7197** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 7198** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 7199** assumes that the strategy may visit at most one row. 7200** 7201** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 7202** SQLite also assumes that if a call to the xUpdate() method is made as 7203** part of the same statement to delete or update a virtual table row and the 7204** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 7205** any database changes. In other words, if the xUpdate() returns 7206** SQLITE_CONSTRAINT, the database contents must be exactly as they were 7207** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 7208** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 7209** the xUpdate method are automatically rolled back by SQLite. 7210** 7211** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 7212** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 7213** If a virtual table extension is 7214** used with an SQLite version earlier than 3.8.2, the results of attempting 7215** to read or write the estimatedRows field are undefined (but are likely 7216** to include crashing the application). The estimatedRows field should 7217** therefore only be used if [sqlite3_libversion_number()] returns a 7218** value greater than or equal to 3008002. Similarly, the idxFlags field 7219** was added for [version 3.9.0] ([dateof:3.9.0]). 7220** It may therefore only be used if 7221** sqlite3_libversion_number() returns a value greater than or equal to 7222** 3009000. 7223*/ 7224struct sqlite3_index_info { 7225 /* Inputs */ 7226 int nConstraint; /* Number of entries in aConstraint */ 7227 struct sqlite3_index_constraint { 7228 int iColumn; /* Column constrained. -1 for ROWID */ 7229 unsigned char op; /* Constraint operator */ 7230 unsigned char usable; /* True if this constraint is usable */ 7231 int iTermOffset; /* Used internally - xBestIndex should ignore */ 7232 } *aConstraint; /* Table of WHERE clause constraints */ 7233 int nOrderBy; /* Number of terms in the ORDER BY clause */ 7234 struct sqlite3_index_orderby { 7235 int iColumn; /* Column number */ 7236 unsigned char desc; /* True for DESC. False for ASC. */ 7237 } *aOrderBy; /* The ORDER BY clause */ 7238 /* Outputs */ 7239 struct sqlite3_index_constraint_usage { 7240 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 7241 unsigned char omit; /* Do not code a test for this constraint */ 7242 } *aConstraintUsage; 7243 int idxNum; /* Number used to identify the index */ 7244 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 7245 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 7246 int orderByConsumed; /* True if output is already ordered */ 7247 double estimatedCost; /* Estimated cost of using this index */ 7248 /* Fields below are only available in SQLite 3.8.2 and later */ 7249 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 7250 /* Fields below are only available in SQLite 3.9.0 and later */ 7251 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 7252 /* Fields below are only available in SQLite 3.10.0 and later */ 7253 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 7254}; 7255 7256/* 7257** CAPI3REF: Virtual Table Scan Flags 7258** 7259** Virtual table implementations are allowed to set the 7260** [sqlite3_index_info].idxFlags field to some combination of 7261** these bits. 7262*/ 7263#define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 7264 7265/* 7266** CAPI3REF: Virtual Table Constraint Operator Codes 7267** 7268** These macros define the allowed values for the 7269** [sqlite3_index_info].aConstraint[].op field. Each value represents 7270** an operator that is part of a constraint term in the WHERE clause of 7271** a query that uses a [virtual table]. 7272** 7273** ^The left-hand operand of the operator is given by the corresponding 7274** aConstraint[].iColumn field. ^An iColumn of -1 indicates the left-hand 7275** operand is the rowid. 7276** The SQLITE_INDEX_CONSTRAINT_LIMIT and SQLITE_INDEX_CONSTRAINT_OFFSET 7277** operators have no left-hand operand, and so for those operators the 7278** corresponding aConstraint[].iColumn is meaningless and should not be 7279** used. 7280** 7281** All operator values from SQLITE_INDEX_CONSTRAINT_FUNCTION through 7282** value 255 are reserved to represent functions that are overloaded 7283** by the [xFindFunction|xFindFunction method] of the virtual table 7284** implementation. 7285** 7286** The right-hand operands for each constraint might be accessible using 7287** the [sqlite3_vtab_rhs_value()] interface. Usually the right-hand 7288** operand is only available if it appears as a single constant literal 7289** in the input SQL. If the right-hand operand is another column or an 7290** expression (even a constant expression) or a parameter, then the 7291** sqlite3_vtab_rhs_value() probably will not be able to extract it. 7292** ^The SQLITE_INDEX_CONSTRAINT_ISNULL and 7293** SQLITE_INDEX_CONSTRAINT_ISNOTNULL operators have no right-hand operand 7294** and hence calls to sqlite3_vtab_rhs_value() for those operators will 7295** always return SQLITE_NOTFOUND. 7296** 7297** The collating sequence to be used for comparison can be found using 7298** the [sqlite3_vtab_collation()] interface. For most real-world virtual 7299** tables, the collating sequence of constraints does not matter (for example 7300** because the constraints are numeric) and so the sqlite3_vtab_collation() 7301** interface is no commonly needed. 7302*/ 7303#define SQLITE_INDEX_CONSTRAINT_EQ 2 7304#define SQLITE_INDEX_CONSTRAINT_GT 4 7305#define SQLITE_INDEX_CONSTRAINT_LE 8 7306#define SQLITE_INDEX_CONSTRAINT_LT 16 7307#define SQLITE_INDEX_CONSTRAINT_GE 32 7308#define SQLITE_INDEX_CONSTRAINT_MATCH 64 7309#define SQLITE_INDEX_CONSTRAINT_LIKE 65 7310#define SQLITE_INDEX_CONSTRAINT_GLOB 66 7311#define SQLITE_INDEX_CONSTRAINT_REGEXP 67 7312#define SQLITE_INDEX_CONSTRAINT_NE 68 7313#define SQLITE_INDEX_CONSTRAINT_ISNOT 69 7314#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 7315#define SQLITE_INDEX_CONSTRAINT_ISNULL 71 7316#define SQLITE_INDEX_CONSTRAINT_IS 72 7317#define SQLITE_INDEX_CONSTRAINT_LIMIT 73 7318#define SQLITE_INDEX_CONSTRAINT_OFFSET 74 7319#define SQLITE_INDEX_CONSTRAINT_FUNCTION 150 7320 7321/* 7322** CAPI3REF: Register A Virtual Table Implementation 7323** METHOD: sqlite3 7324** 7325** ^These routines are used to register a new [virtual table module] name. 7326** ^Module names must be registered before 7327** creating a new [virtual table] using the module and before using a 7328** preexisting [virtual table] for the module. 7329** 7330** ^The module name is registered on the [database connection] specified 7331** by the first parameter. ^The name of the module is given by the 7332** second parameter. ^The third parameter is a pointer to 7333** the implementation of the [virtual table module]. ^The fourth 7334** parameter is an arbitrary client data pointer that is passed through 7335** into the [xCreate] and [xConnect] methods of the virtual table module 7336** when a new virtual table is be being created or reinitialized. 7337** 7338** ^The sqlite3_create_module_v2() interface has a fifth parameter which 7339** is a pointer to a destructor for the pClientData. ^SQLite will 7340** invoke the destructor function (if it is not NULL) when SQLite 7341** no longer needs the pClientData pointer. ^The destructor will also 7342** be invoked if the call to sqlite3_create_module_v2() fails. 7343** ^The sqlite3_create_module() 7344** interface is equivalent to sqlite3_create_module_v2() with a NULL 7345** destructor. 7346** 7347** ^If the third parameter (the pointer to the sqlite3_module object) is 7348** NULL then no new module is created and any existing modules with the 7349** same name are dropped. 7350** 7351** See also: [sqlite3_drop_modules()] 7352*/ 7353SQLITE_API int sqlite3_create_module( 7354 sqlite3 *db, /* SQLite connection to register module with */ 7355 const char *zName, /* Name of the module */ 7356 const sqlite3_module *p, /* Methods for the module */ 7357 void *pClientData /* Client data for xCreate/xConnect */ 7358); 7359SQLITE_API int sqlite3_create_module_v2( 7360 sqlite3 *db, /* SQLite connection to register module with */ 7361 const char *zName, /* Name of the module */ 7362 const sqlite3_module *p, /* Methods for the module */ 7363 void *pClientData, /* Client data for xCreate/xConnect */ 7364 void(*xDestroy)(void*) /* Module destructor function */ 7365); 7366 7367/* 7368** CAPI3REF: Remove Unnecessary Virtual Table Implementations 7369** METHOD: sqlite3 7370** 7371** ^The sqlite3_drop_modules(D,L) interface removes all virtual 7372** table modules from database connection D except those named on list L. 7373** The L parameter must be either NULL or a pointer to an array of pointers 7374** to strings where the array is terminated by a single NULL pointer. 7375** ^If the L parameter is NULL, then all virtual table modules are removed. 7376** 7377** See also: [sqlite3_create_module()] 7378*/ 7379SQLITE_API int sqlite3_drop_modules( 7380 sqlite3 *db, /* Remove modules from this connection */ 7381 const char **azKeep /* Except, do not remove the ones named here */ 7382); 7383 7384/* 7385** CAPI3REF: Virtual Table Instance Object 7386** KEYWORDS: sqlite3_vtab 7387** 7388** Every [virtual table module] implementation uses a subclass 7389** of this object to describe a particular instance 7390** of the [virtual table]. Each subclass will 7391** be tailored to the specific needs of the module implementation. 7392** The purpose of this superclass is to define certain fields that are 7393** common to all module implementations. 7394** 7395** ^Virtual tables methods can set an error message by assigning a 7396** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 7397** take care that any prior string is freed by a call to [sqlite3_free()] 7398** prior to assigning a new string to zErrMsg. ^After the error message 7399** is delivered up to the client application, the string will be automatically 7400** freed by sqlite3_free() and the zErrMsg field will be zeroed. 7401*/ 7402struct sqlite3_vtab { 7403 const sqlite3_module *pModule; /* The module for this virtual table */ 7404 int nRef; /* Number of open cursors */ 7405 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 7406 /* Virtual table implementations will typically add additional fields */ 7407}; 7408 7409/* 7410** CAPI3REF: Virtual Table Cursor Object 7411** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 7412** 7413** Every [virtual table module] implementation uses a subclass of the 7414** following structure to describe cursors that point into the 7415** [virtual table] and are used 7416** to loop through the virtual table. Cursors are created using the 7417** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 7418** by the [sqlite3_module.xClose | xClose] method. Cursors are used 7419** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 7420** of the module. Each module implementation will define 7421** the content of a cursor structure to suit its own needs. 7422** 7423** This superclass exists in order to define fields of the cursor that 7424** are common to all implementations. 7425*/ 7426struct sqlite3_vtab_cursor { 7427 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 7428 /* Virtual table implementations will typically add additional fields */ 7429}; 7430 7431/* 7432** CAPI3REF: Declare The Schema Of A Virtual Table 7433** 7434** ^The [xCreate] and [xConnect] methods of a 7435** [virtual table module] call this interface 7436** to declare the format (the names and datatypes of the columns) of 7437** the virtual tables they implement. 7438*/ 7439SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 7440 7441/* 7442** CAPI3REF: Overload A Function For A Virtual Table 7443** METHOD: sqlite3 7444** 7445** ^(Virtual tables can provide alternative implementations of functions 7446** using the [xFindFunction] method of the [virtual table module]. 7447** But global versions of those functions 7448** must exist in order to be overloaded.)^ 7449** 7450** ^(This API makes sure a global version of a function with a particular 7451** name and number of parameters exists. If no such function exists 7452** before this API is called, a new function is created.)^ ^The implementation 7453** of the new function always causes an exception to be thrown. So 7454** the new function is not good for anything by itself. Its only 7455** purpose is to be a placeholder function that can be overloaded 7456** by a [virtual table]. 7457*/ 7458SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 7459 7460/* 7461** The interface to the virtual-table mechanism defined above (back up 7462** to a comment remarkably similar to this one) is currently considered 7463** to be experimental. The interface might change in incompatible ways. 7464** If this is a problem for you, do not use the interface at this time. 7465** 7466** When the virtual-table mechanism stabilizes, we will declare the 7467** interface fixed, support it indefinitely, and remove this comment. 7468*/ 7469 7470/* 7471** CAPI3REF: A Handle To An Open BLOB 7472** KEYWORDS: {BLOB handle} {BLOB handles} 7473** 7474** An instance of this object represents an open BLOB on which 7475** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 7476** ^Objects of this type are created by [sqlite3_blob_open()] 7477** and destroyed by [sqlite3_blob_close()]. 7478** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 7479** can be used to read or write small subsections of the BLOB. 7480** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 7481*/ 7482typedef struct sqlite3_blob sqlite3_blob; 7483 7484/* 7485** CAPI3REF: Open A BLOB For Incremental I/O 7486** METHOD: sqlite3 7487** CONSTRUCTOR: sqlite3_blob 7488** 7489** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 7490** in row iRow, column zColumn, table zTable in database zDb; 7491** in other words, the same BLOB that would be selected by: 7492** 7493** <pre> 7494** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 7495** </pre>)^ 7496** 7497** ^(Parameter zDb is not the filename that contains the database, but 7498** rather the symbolic name of the database. For attached databases, this is 7499** the name that appears after the AS keyword in the [ATTACH] statement. 7500** For the main database file, the database name is "main". For TEMP 7501** tables, the database name is "temp".)^ 7502** 7503** ^If the flags parameter is non-zero, then the BLOB is opened for read 7504** and write access. ^If the flags parameter is zero, the BLOB is opened for 7505** read-only access. 7506** 7507** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 7508** in *ppBlob. Otherwise an [error code] is returned and, unless the error 7509** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 7510** the API is not misused, it is always safe to call [sqlite3_blob_close()] 7511** on *ppBlob after this function it returns. 7512** 7513** This function fails with SQLITE_ERROR if any of the following are true: 7514** <ul> 7515** <li> ^(Database zDb does not exist)^, 7516** <li> ^(Table zTable does not exist within database zDb)^, 7517** <li> ^(Table zTable is a WITHOUT ROWID table)^, 7518** <li> ^(Column zColumn does not exist)^, 7519** <li> ^(Row iRow is not present in the table)^, 7520** <li> ^(The specified column of row iRow contains a value that is not 7521** a TEXT or BLOB value)^, 7522** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 7523** constraint and the blob is being opened for read/write access)^, 7524** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 7525** column zColumn is part of a [child key] definition and the blob is 7526** being opened for read/write access)^. 7527** </ul> 7528** 7529** ^Unless it returns SQLITE_MISUSE, this function sets the 7530** [database connection] error code and message accessible via 7531** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7532** 7533** A BLOB referenced by sqlite3_blob_open() may be read using the 7534** [sqlite3_blob_read()] interface and modified by using 7535** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 7536** different row of the same table using the [sqlite3_blob_reopen()] 7537** interface. However, the column, table, or database of a [BLOB handle] 7538** cannot be changed after the [BLOB handle] is opened. 7539** 7540** ^(If the row that a BLOB handle points to is modified by an 7541** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 7542** then the BLOB handle is marked as "expired". 7543** This is true if any column of the row is changed, even a column 7544** other than the one the BLOB handle is open on.)^ 7545** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 7546** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 7547** ^(Changes written into a BLOB prior to the BLOB expiring are not 7548** rolled back by the expiration of the BLOB. Such changes will eventually 7549** commit if the transaction continues to completion.)^ 7550** 7551** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 7552** the opened blob. ^The size of a blob may not be changed by this 7553** interface. Use the [UPDATE] SQL command to change the size of a 7554** blob. 7555** 7556** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 7557** and the built-in [zeroblob] SQL function may be used to create a 7558** zero-filled blob to read or write using the incremental-blob interface. 7559** 7560** To avoid a resource leak, every open [BLOB handle] should eventually 7561** be released by a call to [sqlite3_blob_close()]. 7562** 7563** See also: [sqlite3_blob_close()], 7564** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 7565** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 7566*/ 7567SQLITE_API int sqlite3_blob_open( 7568 sqlite3*, 7569 const char *zDb, 7570 const char *zTable, 7571 const char *zColumn, 7572 sqlite3_int64 iRow, 7573 int flags, 7574 sqlite3_blob **ppBlob 7575); 7576 7577/* 7578** CAPI3REF: Move a BLOB Handle to a New Row 7579** METHOD: sqlite3_blob 7580** 7581** ^This function is used to move an existing [BLOB handle] so that it points 7582** to a different row of the same database table. ^The new row is identified 7583** by the rowid value passed as the second argument. Only the row can be 7584** changed. ^The database, table and column on which the blob handle is open 7585** remain the same. Moving an existing [BLOB handle] to a new row is 7586** faster than closing the existing handle and opening a new one. 7587** 7588** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 7589** it must exist and there must be either a blob or text value stored in 7590** the nominated column.)^ ^If the new row is not present in the table, or if 7591** it does not contain a blob or text value, or if another error occurs, an 7592** SQLite error code is returned and the blob handle is considered aborted. 7593** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 7594** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 7595** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 7596** always returns zero. 7597** 7598** ^This function sets the database handle error code and message. 7599*/ 7600SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 7601 7602/* 7603** CAPI3REF: Close A BLOB Handle 7604** DESTRUCTOR: sqlite3_blob 7605** 7606** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 7607** unconditionally. Even if this routine returns an error code, the 7608** handle is still closed.)^ 7609** 7610** ^If the blob handle being closed was opened for read-write access, and if 7611** the database is in auto-commit mode and there are no other open read-write 7612** blob handles or active write statements, the current transaction is 7613** committed. ^If an error occurs while committing the transaction, an error 7614** code is returned and the transaction rolled back. 7615** 7616** Calling this function with an argument that is not a NULL pointer or an 7617** open blob handle results in undefined behaviour. ^Calling this routine 7618** with a null pointer (such as would be returned by a failed call to 7619** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 7620** is passed a valid open blob handle, the values returned by the 7621** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 7622*/ 7623SQLITE_API int sqlite3_blob_close(sqlite3_blob *); 7624 7625/* 7626** CAPI3REF: Return The Size Of An Open BLOB 7627** METHOD: sqlite3_blob 7628** 7629** ^Returns the size in bytes of the BLOB accessible via the 7630** successfully opened [BLOB handle] in its only argument. ^The 7631** incremental blob I/O routines can only read or overwriting existing 7632** blob content; they cannot change the size of a blob. 7633** 7634** This routine only works on a [BLOB handle] which has been created 7635** by a prior successful call to [sqlite3_blob_open()] and which has not 7636** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7637** to this routine results in undefined and probably undesirable behavior. 7638*/ 7639SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 7640 7641/* 7642** CAPI3REF: Read Data From A BLOB Incrementally 7643** METHOD: sqlite3_blob 7644** 7645** ^(This function is used to read data from an open [BLOB handle] into a 7646** caller-supplied buffer. N bytes of data are copied into buffer Z 7647** from the open BLOB, starting at offset iOffset.)^ 7648** 7649** ^If offset iOffset is less than N bytes from the end of the BLOB, 7650** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 7651** less than zero, [SQLITE_ERROR] is returned and no data is read. 7652** ^The size of the blob (and hence the maximum value of N+iOffset) 7653** can be determined using the [sqlite3_blob_bytes()] interface. 7654** 7655** ^An attempt to read from an expired [BLOB handle] fails with an 7656** error code of [SQLITE_ABORT]. 7657** 7658** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 7659** Otherwise, an [error code] or an [extended error code] is returned.)^ 7660** 7661** This routine only works on a [BLOB handle] which has been created 7662** by a prior successful call to [sqlite3_blob_open()] and which has not 7663** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7664** to this routine results in undefined and probably undesirable behavior. 7665** 7666** See also: [sqlite3_blob_write()]. 7667*/ 7668SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 7669 7670/* 7671** CAPI3REF: Write Data Into A BLOB Incrementally 7672** METHOD: sqlite3_blob 7673** 7674** ^(This function is used to write data into an open [BLOB handle] from a 7675** caller-supplied buffer. N bytes of data are copied from the buffer Z 7676** into the open BLOB, starting at offset iOffset.)^ 7677** 7678** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 7679** Otherwise, an [error code] or an [extended error code] is returned.)^ 7680** ^Unless SQLITE_MISUSE is returned, this function sets the 7681** [database connection] error code and message accessible via 7682** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7683** 7684** ^If the [BLOB handle] passed as the first argument was not opened for 7685** writing (the flags parameter to [sqlite3_blob_open()] was zero), 7686** this function returns [SQLITE_READONLY]. 7687** 7688** This function may only modify the contents of the BLOB; it is 7689** not possible to increase the size of a BLOB using this API. 7690** ^If offset iOffset is less than N bytes from the end of the BLOB, 7691** [SQLITE_ERROR] is returned and no data is written. The size of the 7692** BLOB (and hence the maximum value of N+iOffset) can be determined 7693** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 7694** than zero [SQLITE_ERROR] is returned and no data is written. 7695** 7696** ^An attempt to write to an expired [BLOB handle] fails with an 7697** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 7698** before the [BLOB handle] expired are not rolled back by the 7699** expiration of the handle, though of course those changes might 7700** have been overwritten by the statement that expired the BLOB handle 7701** or by other independent statements. 7702** 7703** This routine only works on a [BLOB handle] which has been created 7704** by a prior successful call to [sqlite3_blob_open()] and which has not 7705** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7706** to this routine results in undefined and probably undesirable behavior. 7707** 7708** See also: [sqlite3_blob_read()]. 7709*/ 7710SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 7711 7712/* 7713** CAPI3REF: Virtual File System Objects 7714** 7715** A virtual filesystem (VFS) is an [sqlite3_vfs] object 7716** that SQLite uses to interact 7717** with the underlying operating system. Most SQLite builds come with a 7718** single default VFS that is appropriate for the host computer. 7719** New VFSes can be registered and existing VFSes can be unregistered. 7720** The following interfaces are provided. 7721** 7722** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 7723** ^Names are case sensitive. 7724** ^Names are zero-terminated UTF-8 strings. 7725** ^If there is no match, a NULL pointer is returned. 7726** ^If zVfsName is NULL then the default VFS is returned. 7727** 7728** ^New VFSes are registered with sqlite3_vfs_register(). 7729** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 7730** ^The same VFS can be registered multiple times without injury. 7731** ^To make an existing VFS into the default VFS, register it again 7732** with the makeDflt flag set. If two different VFSes with the 7733** same name are registered, the behavior is undefined. If a 7734** VFS is registered with a name that is NULL or an empty string, 7735** then the behavior is undefined. 7736** 7737** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 7738** ^(If the default VFS is unregistered, another VFS is chosen as 7739** the default. The choice for the new VFS is arbitrary.)^ 7740*/ 7741SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 7742SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 7743SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 7744 7745/* 7746** CAPI3REF: Mutexes 7747** 7748** The SQLite core uses these routines for thread 7749** synchronization. Though they are intended for internal 7750** use by SQLite, code that links against SQLite is 7751** permitted to use any of these routines. 7752** 7753** The SQLite source code contains multiple implementations 7754** of these mutex routines. An appropriate implementation 7755** is selected automatically at compile-time. The following 7756** implementations are available in the SQLite core: 7757** 7758** <ul> 7759** <li> SQLITE_MUTEX_PTHREADS 7760** <li> SQLITE_MUTEX_W32 7761** <li> SQLITE_MUTEX_NOOP 7762** </ul> 7763** 7764** The SQLITE_MUTEX_NOOP implementation is a set of routines 7765** that does no real locking and is appropriate for use in 7766** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 7767** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 7768** and Windows. 7769** 7770** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 7771** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 7772** implementation is included with the library. In this case the 7773** application must supply a custom mutex implementation using the 7774** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 7775** before calling sqlite3_initialize() or any other public sqlite3_ 7776** function that calls sqlite3_initialize(). 7777** 7778** ^The sqlite3_mutex_alloc() routine allocates a new 7779** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 7780** routine returns NULL if it is unable to allocate the requested 7781** mutex. The argument to sqlite3_mutex_alloc() must one of these 7782** integer constants: 7783** 7784** <ul> 7785** <li> SQLITE_MUTEX_FAST 7786** <li> SQLITE_MUTEX_RECURSIVE 7787** <li> SQLITE_MUTEX_STATIC_MAIN 7788** <li> SQLITE_MUTEX_STATIC_MEM 7789** <li> SQLITE_MUTEX_STATIC_OPEN 7790** <li> SQLITE_MUTEX_STATIC_PRNG 7791** <li> SQLITE_MUTEX_STATIC_LRU 7792** <li> SQLITE_MUTEX_STATIC_PMEM 7793** <li> SQLITE_MUTEX_STATIC_APP1 7794** <li> SQLITE_MUTEX_STATIC_APP2 7795** <li> SQLITE_MUTEX_STATIC_APP3 7796** <li> SQLITE_MUTEX_STATIC_VFS1 7797** <li> SQLITE_MUTEX_STATIC_VFS2 7798** <li> SQLITE_MUTEX_STATIC_VFS3 7799** </ul> 7800** 7801** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 7802** cause sqlite3_mutex_alloc() to create 7803** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 7804** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 7805** The mutex implementation does not need to make a distinction 7806** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 7807** not want to. SQLite will only request a recursive mutex in 7808** cases where it really needs one. If a faster non-recursive mutex 7809** implementation is available on the host platform, the mutex subsystem 7810** might return such a mutex in response to SQLITE_MUTEX_FAST. 7811** 7812** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 7813** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 7814** a pointer to a static preexisting mutex. ^Nine static mutexes are 7815** used by the current version of SQLite. Future versions of SQLite 7816** may add additional static mutexes. Static mutexes are for internal 7817** use by SQLite only. Applications that use SQLite mutexes should 7818** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 7819** SQLITE_MUTEX_RECURSIVE. 7820** 7821** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 7822** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 7823** returns a different mutex on every call. ^For the static 7824** mutex types, the same mutex is returned on every call that has 7825** the same type number. 7826** 7827** ^The sqlite3_mutex_free() routine deallocates a previously 7828** allocated dynamic mutex. Attempting to deallocate a static 7829** mutex results in undefined behavior. 7830** 7831** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 7832** to enter a mutex. ^If another thread is already within the mutex, 7833** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 7834** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 7835** upon successful entry. ^(Mutexes created using 7836** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 7837** In such cases, the 7838** mutex must be exited an equal number of times before another thread 7839** can enter.)^ If the same thread tries to enter any mutex other 7840** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 7841** 7842** ^(Some systems (for example, Windows 95) do not support the operation 7843** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 7844** will always return SQLITE_BUSY. The SQLite core only ever uses 7845** sqlite3_mutex_try() as an optimization so this is acceptable 7846** behavior.)^ 7847** 7848** ^The sqlite3_mutex_leave() routine exits a mutex that was 7849** previously entered by the same thread. The behavior 7850** is undefined if the mutex is not currently entered by the 7851** calling thread or is not currently allocated. 7852** 7853** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 7854** sqlite3_mutex_leave() is a NULL pointer, then all three routines 7855** behave as no-ops. 7856** 7857** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 7858*/ 7859SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 7860SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 7861SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 7862SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 7863SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 7864 7865/* 7866** CAPI3REF: Mutex Methods Object 7867** 7868** An instance of this structure defines the low-level routines 7869** used to allocate and use mutexes. 7870** 7871** Usually, the default mutex implementations provided by SQLite are 7872** sufficient, however the application has the option of substituting a custom 7873** implementation for specialized deployments or systems for which SQLite 7874** does not provide a suitable implementation. In this case, the application 7875** creates and populates an instance of this structure to pass 7876** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 7877** Additionally, an instance of this structure can be used as an 7878** output variable when querying the system for the current mutex 7879** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 7880** 7881** ^The xMutexInit method defined by this structure is invoked as 7882** part of system initialization by the sqlite3_initialize() function. 7883** ^The xMutexInit routine is called by SQLite exactly once for each 7884** effective call to [sqlite3_initialize()]. 7885** 7886** ^The xMutexEnd method defined by this structure is invoked as 7887** part of system shutdown by the sqlite3_shutdown() function. The 7888** implementation of this method is expected to release all outstanding 7889** resources obtained by the mutex methods implementation, especially 7890** those obtained by the xMutexInit method. ^The xMutexEnd() 7891** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 7892** 7893** ^(The remaining seven methods defined by this structure (xMutexAlloc, 7894** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 7895** xMutexNotheld) implement the following interfaces (respectively): 7896** 7897** <ul> 7898** <li> [sqlite3_mutex_alloc()] </li> 7899** <li> [sqlite3_mutex_free()] </li> 7900** <li> [sqlite3_mutex_enter()] </li> 7901** <li> [sqlite3_mutex_try()] </li> 7902** <li> [sqlite3_mutex_leave()] </li> 7903** <li> [sqlite3_mutex_held()] </li> 7904** <li> [sqlite3_mutex_notheld()] </li> 7905** </ul>)^ 7906** 7907** The only difference is that the public sqlite3_XXX functions enumerated 7908** above silently ignore any invocations that pass a NULL pointer instead 7909** of a valid mutex handle. The implementations of the methods defined 7910** by this structure are not required to handle this case. The results 7911** of passing a NULL pointer instead of a valid mutex handle are undefined 7912** (i.e. it is acceptable to provide an implementation that segfaults if 7913** it is passed a NULL pointer). 7914** 7915** The xMutexInit() method must be threadsafe. It must be harmless to 7916** invoke xMutexInit() multiple times within the same process and without 7917** intervening calls to xMutexEnd(). Second and subsequent calls to 7918** xMutexInit() must be no-ops. 7919** 7920** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 7921** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 7922** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 7923** memory allocation for a fast or recursive mutex. 7924** 7925** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 7926** called, but only if the prior call to xMutexInit returned SQLITE_OK. 7927** If xMutexInit fails in any way, it is expected to clean up after itself 7928** prior to returning. 7929*/ 7930typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 7931struct sqlite3_mutex_methods { 7932 int (*xMutexInit)(void); 7933 int (*xMutexEnd)(void); 7934 sqlite3_mutex *(*xMutexAlloc)(int); 7935 void (*xMutexFree)(sqlite3_mutex *); 7936 void (*xMutexEnter)(sqlite3_mutex *); 7937 int (*xMutexTry)(sqlite3_mutex *); 7938 void (*xMutexLeave)(sqlite3_mutex *); 7939 int (*xMutexHeld)(sqlite3_mutex *); 7940 int (*xMutexNotheld)(sqlite3_mutex *); 7941}; 7942 7943/* 7944** CAPI3REF: Mutex Verification Routines 7945** 7946** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 7947** are intended for use inside assert() statements. The SQLite core 7948** never uses these routines except inside an assert() and applications 7949** are advised to follow the lead of the core. The SQLite core only 7950** provides implementations for these routines when it is compiled 7951** with the SQLITE_DEBUG flag. External mutex implementations 7952** are only required to provide these routines if SQLITE_DEBUG is 7953** defined and if NDEBUG is not defined. 7954** 7955** These routines should return true if the mutex in their argument 7956** is held or not held, respectively, by the calling thread. 7957** 7958** The implementation is not required to provide versions of these 7959** routines that actually work. If the implementation does not provide working 7960** versions of these routines, it should at least provide stubs that always 7961** return true so that one does not get spurious assertion failures. 7962** 7963** If the argument to sqlite3_mutex_held() is a NULL pointer then 7964** the routine should return 1. This seems counter-intuitive since 7965** clearly the mutex cannot be held if it does not exist. But 7966** the reason the mutex does not exist is because the build is not 7967** using mutexes. And we do not want the assert() containing the 7968** call to sqlite3_mutex_held() to fail, so a non-zero return is 7969** the appropriate thing to do. The sqlite3_mutex_notheld() 7970** interface should also return 1 when given a NULL pointer. 7971*/ 7972#ifndef NDEBUG 7973SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 7974SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 7975#endif 7976 7977/* 7978** CAPI3REF: Mutex Types 7979** 7980** The [sqlite3_mutex_alloc()] interface takes a single argument 7981** which is one of these integer constants. 7982** 7983** The set of static mutexes may change from one SQLite release to the 7984** next. Applications that override the built-in mutex logic must be 7985** prepared to accommodate additional static mutexes. 7986*/ 7987#define SQLITE_MUTEX_FAST 0 7988#define SQLITE_MUTEX_RECURSIVE 1 7989#define SQLITE_MUTEX_STATIC_MAIN 2 7990#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 7991#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 7992#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 7993#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 7994#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 7995#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 7996#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 7997#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 7998#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 7999#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 8000#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 8001#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 8002#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 8003 8004/* Legacy compatibility: */ 8005#define SQLITE_MUTEX_STATIC_MASTER 2 8006 8007 8008/* 8009** CAPI3REF: Retrieve the mutex for a database connection 8010** METHOD: sqlite3 8011** 8012** ^This interface returns a pointer the [sqlite3_mutex] object that 8013** serializes access to the [database connection] given in the argument 8014** when the [threading mode] is Serialized. 8015** ^If the [threading mode] is Single-thread or Multi-thread then this 8016** routine returns a NULL pointer. 8017*/ 8018SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 8019 8020/* 8021** CAPI3REF: Low-Level Control Of Database Files 8022** METHOD: sqlite3 8023** KEYWORDS: {file control} 8024** 8025** ^The [sqlite3_file_control()] interface makes a direct call to the 8026** xFileControl method for the [sqlite3_io_methods] object associated 8027** with a particular database identified by the second argument. ^The 8028** name of the database is "main" for the main database or "temp" for the 8029** TEMP database, or the name that appears after the AS keyword for 8030** databases that are added using the [ATTACH] SQL command. 8031** ^A NULL pointer can be used in place of "main" to refer to the 8032** main database file. 8033** ^The third and fourth parameters to this routine 8034** are passed directly through to the second and third parameters of 8035** the xFileControl method. ^The return value of the xFileControl 8036** method becomes the return value of this routine. 8037** 8038** A few opcodes for [sqlite3_file_control()] are handled directly 8039** by the SQLite core and never invoke the 8040** sqlite3_io_methods.xFileControl method. 8041** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes 8042** a pointer to the underlying [sqlite3_file] object to be written into 8043** the space pointed to by the 4th parameter. The 8044** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns 8045** the [sqlite3_file] object associated with the journal file instead of 8046** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns 8047** a pointer to the underlying [sqlite3_vfs] object for the file. 8048** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter 8049** from the pager. 8050** 8051** ^If the second parameter (zDbName) does not match the name of any 8052** open database file, then SQLITE_ERROR is returned. ^This error 8053** code is not remembered and will not be recalled by [sqlite3_errcode()] 8054** or [sqlite3_errmsg()]. The underlying xFileControl method might 8055** also return SQLITE_ERROR. There is no way to distinguish between 8056** an incorrect zDbName and an SQLITE_ERROR return from the underlying 8057** xFileControl method. 8058** 8059** See also: [file control opcodes] 8060*/ 8061SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 8062 8063/* 8064** CAPI3REF: Testing Interface 8065** 8066** ^The sqlite3_test_control() interface is used to read out internal 8067** state of SQLite and to inject faults into SQLite for testing 8068** purposes. ^The first parameter is an operation code that determines 8069** the number, meaning, and operation of all subsequent parameters. 8070** 8071** This interface is not for use by applications. It exists solely 8072** for verifying the correct operation of the SQLite library. Depending 8073** on how the SQLite library is compiled, this interface might not exist. 8074** 8075** The details of the operation codes, their meanings, the parameters 8076** they take, and what they do are all subject to change without notice. 8077** Unlike most of the SQLite API, this function is not guaranteed to 8078** operate consistently from one release to the next. 8079*/ 8080SQLITE_API int sqlite3_test_control(int op, ...); 8081 8082/* 8083** CAPI3REF: Testing Interface Operation Codes 8084** 8085** These constants are the valid operation code parameters used 8086** as the first argument to [sqlite3_test_control()]. 8087** 8088** These parameters and their meanings are subject to change 8089** without notice. These values are for testing purposes only. 8090** Applications should not use any of these parameters or the 8091** [sqlite3_test_control()] interface. 8092*/ 8093#define SQLITE_TESTCTRL_FIRST 5 8094#define SQLITE_TESTCTRL_PRNG_SAVE 5 8095#define SQLITE_TESTCTRL_PRNG_RESTORE 6 8096#define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */ 8097#define SQLITE_TESTCTRL_BITVEC_TEST 8 8098#define SQLITE_TESTCTRL_FAULT_INSTALL 9 8099#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 8100#define SQLITE_TESTCTRL_PENDING_BYTE 11 8101#define SQLITE_TESTCTRL_ASSERT 12 8102#define SQLITE_TESTCTRL_ALWAYS 13 8103#define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */ 8104#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 8105#define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */ 8106#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 8107#define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17 8108#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 8109#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 8110#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 8111#define SQLITE_TESTCTRL_NEVER_CORRUPT 20 8112#define SQLITE_TESTCTRL_VDBE_COVERAGE 21 8113#define SQLITE_TESTCTRL_BYTEORDER 22 8114#define SQLITE_TESTCTRL_ISINIT 23 8115#define SQLITE_TESTCTRL_SORTER_MMAP 24 8116#define SQLITE_TESTCTRL_IMPOSTER 25 8117#define SQLITE_TESTCTRL_PARSER_COVERAGE 26 8118#define SQLITE_TESTCTRL_RESULT_INTREAL 27 8119#define SQLITE_TESTCTRL_PRNG_SEED 28 8120#define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29 8121#define SQLITE_TESTCTRL_SEEK_COUNT 30 8122#define SQLITE_TESTCTRL_TRACEFLAGS 31 8123#define SQLITE_TESTCTRL_TUNE 32 8124#define SQLITE_TESTCTRL_LOGEST 33 8125#define SQLITE_TESTCTRL_LAST 33 /* Largest TESTCTRL */ 8126 8127/* 8128** CAPI3REF: SQL Keyword Checking 8129** 8130** These routines provide access to the set of SQL language keywords 8131** recognized by SQLite. Applications can uses these routines to determine 8132** whether or not a specific identifier needs to be escaped (for example, 8133** by enclosing in double-quotes) so as not to confuse the parser. 8134** 8135** The sqlite3_keyword_count() interface returns the number of distinct 8136** keywords understood by SQLite. 8137** 8138** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and 8139** makes *Z point to that keyword expressed as UTF8 and writes the number 8140** of bytes in the keyword into *L. The string that *Z points to is not 8141** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns 8142** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z 8143** or L are NULL or invalid pointers then calls to 8144** sqlite3_keyword_name(N,Z,L) result in undefined behavior. 8145** 8146** The sqlite3_keyword_check(Z,L) interface checks to see whether or not 8147** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero 8148** if it is and zero if not. 8149** 8150** The parser used by SQLite is forgiving. It is often possible to use 8151** a keyword as an identifier as long as such use does not result in a 8152** parsing ambiguity. For example, the statement 8153** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and 8154** creates a new table named "BEGIN" with three columns named 8155** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid 8156** using keywords as identifiers. Common techniques used to avoid keyword 8157** name collisions include: 8158** <ul> 8159** <li> Put all identifier names inside double-quotes. This is the official 8160** SQL way to escape identifier names. 8161** <li> Put identifier names inside [...]. This is not standard SQL, 8162** but it is what SQL Server does and so lots of programmers use this 8163** technique. 8164** <li> Begin every identifier with the letter "Z" as no SQL keywords start 8165** with "Z". 8166** <li> Include a digit somewhere in every identifier name. 8167** </ul> 8168** 8169** Note that the number of keywords understood by SQLite can depend on 8170** compile-time options. For example, "VACUUM" is not a keyword if 8171** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also, 8172** new keywords may be added to future releases of SQLite. 8173*/ 8174SQLITE_API int sqlite3_keyword_count(void); 8175SQLITE_API int sqlite3_keyword_name(int,const char**,int*); 8176SQLITE_API int sqlite3_keyword_check(const char*,int); 8177 8178/* 8179** CAPI3REF: Dynamic String Object 8180** KEYWORDS: {dynamic string} 8181** 8182** An instance of the sqlite3_str object contains a dynamically-sized 8183** string under construction. 8184** 8185** The lifecycle of an sqlite3_str object is as follows: 8186** <ol> 8187** <li> ^The sqlite3_str object is created using [sqlite3_str_new()]. 8188** <li> ^Text is appended to the sqlite3_str object using various 8189** methods, such as [sqlite3_str_appendf()]. 8190** <li> ^The sqlite3_str object is destroyed and the string it created 8191** is returned using the [sqlite3_str_finish()] interface. 8192** </ol> 8193*/ 8194typedef struct sqlite3_str sqlite3_str; 8195 8196/* 8197** CAPI3REF: Create A New Dynamic String Object 8198** CONSTRUCTOR: sqlite3_str 8199** 8200** ^The [sqlite3_str_new(D)] interface allocates and initializes 8201** a new [sqlite3_str] object. To avoid memory leaks, the object returned by 8202** [sqlite3_str_new()] must be freed by a subsequent call to 8203** [sqlite3_str_finish(X)]. 8204** 8205** ^The [sqlite3_str_new(D)] interface always returns a pointer to a 8206** valid [sqlite3_str] object, though in the event of an out-of-memory 8207** error the returned object might be a special singleton that will 8208** silently reject new text, always return SQLITE_NOMEM from 8209** [sqlite3_str_errcode()], always return 0 for 8210** [sqlite3_str_length()], and always return NULL from 8211** [sqlite3_str_finish(X)]. It is always safe to use the value 8212** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter 8213** to any of the other [sqlite3_str] methods. 8214** 8215** The D parameter to [sqlite3_str_new(D)] may be NULL. If the 8216** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum 8217** length of the string contained in the [sqlite3_str] object will be 8218** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead 8219** of [SQLITE_MAX_LENGTH]. 8220*/ 8221SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*); 8222 8223/* 8224** CAPI3REF: Finalize A Dynamic String 8225** DESTRUCTOR: sqlite3_str 8226** 8227** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X 8228** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()] 8229** that contains the constructed string. The calling application should 8230** pass the returned value to [sqlite3_free()] to avoid a memory leak. 8231** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any 8232** errors were encountered during construction of the string. ^The 8233** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the 8234** string in [sqlite3_str] object X is zero bytes long. 8235*/ 8236SQLITE_API char *sqlite3_str_finish(sqlite3_str*); 8237 8238/* 8239** CAPI3REF: Add Content To A Dynamic String 8240** METHOD: sqlite3_str 8241** 8242** These interfaces add content to an sqlite3_str object previously obtained 8243** from [sqlite3_str_new()]. 8244** 8245** ^The [sqlite3_str_appendf(X,F,...)] and 8246** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf] 8247** functionality of SQLite to append formatted text onto the end of 8248** [sqlite3_str] object X. 8249** 8250** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S 8251** onto the end of the [sqlite3_str] object X. N must be non-negative. 8252** S must contain at least N non-zero bytes of content. To append a 8253** zero-terminated string in its entirety, use the [sqlite3_str_appendall()] 8254** method instead. 8255** 8256** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of 8257** zero-terminated string S onto the end of [sqlite3_str] object X. 8258** 8259** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the 8260** single-byte character C onto the end of [sqlite3_str] object X. 8261** ^This method can be used, for example, to add whitespace indentation. 8262** 8263** ^The [sqlite3_str_reset(X)] method resets the string under construction 8264** inside [sqlite3_str] object X back to zero bytes in length. 8265** 8266** These methods do not return a result code. ^If an error occurs, that fact 8267** is recorded in the [sqlite3_str] object and can be recovered by a 8268** subsequent call to [sqlite3_str_errcode(X)]. 8269*/ 8270SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...); 8271SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list); 8272SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N); 8273SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn); 8274SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C); 8275SQLITE_API void sqlite3_str_reset(sqlite3_str*); 8276 8277/* 8278** CAPI3REF: Status Of A Dynamic String 8279** METHOD: sqlite3_str 8280** 8281** These interfaces return the current status of an [sqlite3_str] object. 8282** 8283** ^If any prior errors have occurred while constructing the dynamic string 8284** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return 8285** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns 8286** [SQLITE_NOMEM] following any out-of-memory error, or 8287** [SQLITE_TOOBIG] if the size of the dynamic string exceeds 8288** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors. 8289** 8290** ^The [sqlite3_str_length(X)] method returns the current length, in bytes, 8291** of the dynamic string under construction in [sqlite3_str] object X. 8292** ^The length returned by [sqlite3_str_length(X)] does not include the 8293** zero-termination byte. 8294** 8295** ^The [sqlite3_str_value(X)] method returns a pointer to the current 8296** content of the dynamic string under construction in X. The value 8297** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X 8298** and might be freed or altered by any subsequent method on the same 8299** [sqlite3_str] object. Applications must not used the pointer returned 8300** [sqlite3_str_value(X)] after any subsequent method call on the same 8301** object. ^Applications may change the content of the string returned 8302** by [sqlite3_str_value(X)] as long as they do not write into any bytes 8303** outside the range of 0 to [sqlite3_str_length(X)] and do not read or 8304** write any byte after any subsequent sqlite3_str method call. 8305*/ 8306SQLITE_API int sqlite3_str_errcode(sqlite3_str*); 8307SQLITE_API int sqlite3_str_length(sqlite3_str*); 8308SQLITE_API char *sqlite3_str_value(sqlite3_str*); 8309 8310/* 8311** CAPI3REF: SQLite Runtime Status 8312** 8313** ^These interfaces are used to retrieve runtime status information 8314** about the performance of SQLite, and optionally to reset various 8315** highwater marks. ^The first argument is an integer code for 8316** the specific parameter to measure. ^(Recognized integer codes 8317** are of the form [status parameters | SQLITE_STATUS_...].)^ 8318** ^The current value of the parameter is returned into *pCurrent. 8319** ^The highest recorded value is returned in *pHighwater. ^If the 8320** resetFlag is true, then the highest record value is reset after 8321** *pHighwater is written. ^(Some parameters do not record the highest 8322** value. For those parameters 8323** nothing is written into *pHighwater and the resetFlag is ignored.)^ 8324** ^(Other parameters record only the highwater mark and not the current 8325** value. For these latter parameters nothing is written into *pCurrent.)^ 8326** 8327** ^The sqlite3_status() and sqlite3_status64() routines return 8328** SQLITE_OK on success and a non-zero [error code] on failure. 8329** 8330** If either the current value or the highwater mark is too large to 8331** be represented by a 32-bit integer, then the values returned by 8332** sqlite3_status() are undefined. 8333** 8334** See also: [sqlite3_db_status()] 8335*/ 8336SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 8337SQLITE_API int sqlite3_status64( 8338 int op, 8339 sqlite3_int64 *pCurrent, 8340 sqlite3_int64 *pHighwater, 8341 int resetFlag 8342); 8343 8344 8345/* 8346** CAPI3REF: Status Parameters 8347** KEYWORDS: {status parameters} 8348** 8349** These integer constants designate various run-time status parameters 8350** that can be returned by [sqlite3_status()]. 8351** 8352** <dl> 8353** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 8354** <dd>This parameter is the current amount of memory checked out 8355** using [sqlite3_malloc()], either directly or indirectly. The 8356** figure includes calls made to [sqlite3_malloc()] by the application 8357** and internal memory usage by the SQLite library. Auxiliary page-cache 8358** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 8359** this parameter. The amount returned is the sum of the allocation 8360** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 8361** 8362** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 8363** <dd>This parameter records the largest memory allocation request 8364** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 8365** internal equivalents). Only the value returned in the 8366** *pHighwater parameter to [sqlite3_status()] is of interest. 8367** The value written into the *pCurrent parameter is undefined.</dd>)^ 8368** 8369** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 8370** <dd>This parameter records the number of separate memory allocations 8371** currently checked out.</dd>)^ 8372** 8373** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 8374** <dd>This parameter returns the number of pages used out of the 8375** [pagecache memory allocator] that was configured using 8376** [SQLITE_CONFIG_PAGECACHE]. The 8377** value returned is in pages, not in bytes.</dd>)^ 8378** 8379** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 8380** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 8381** <dd>This parameter returns the number of bytes of page cache 8382** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 8383** buffer and where forced to overflow to [sqlite3_malloc()]. The 8384** returned value includes allocations that overflowed because they 8385** where too large (they were larger than the "sz" parameter to 8386** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 8387** no space was left in the page cache.</dd>)^ 8388** 8389** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 8390** <dd>This parameter records the largest memory allocation request 8391** handed to the [pagecache memory allocator]. Only the value returned in the 8392** *pHighwater parameter to [sqlite3_status()] is of interest. 8393** The value written into the *pCurrent parameter is undefined.</dd>)^ 8394** 8395** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 8396** <dd>No longer used.</dd> 8397** 8398** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 8399** <dd>No longer used.</dd> 8400** 8401** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 8402** <dd>No longer used.</dd> 8403** 8404** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 8405** <dd>The *pHighwater parameter records the deepest parser stack. 8406** The *pCurrent value is undefined. The *pHighwater value is only 8407** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 8408** </dl> 8409** 8410** New status parameters may be added from time to time. 8411*/ 8412#define SQLITE_STATUS_MEMORY_USED 0 8413#define SQLITE_STATUS_PAGECACHE_USED 1 8414#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 8415#define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 8416#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 8417#define SQLITE_STATUS_MALLOC_SIZE 5 8418#define SQLITE_STATUS_PARSER_STACK 6 8419#define SQLITE_STATUS_PAGECACHE_SIZE 7 8420#define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 8421#define SQLITE_STATUS_MALLOC_COUNT 9 8422 8423/* 8424** CAPI3REF: Database Connection Status 8425** METHOD: sqlite3 8426** 8427** ^This interface is used to retrieve runtime status information 8428** about a single [database connection]. ^The first argument is the 8429** database connection object to be interrogated. ^The second argument 8430** is an integer constant, taken from the set of 8431** [SQLITE_DBSTATUS options], that 8432** determines the parameter to interrogate. The set of 8433** [SQLITE_DBSTATUS options] is likely 8434** to grow in future releases of SQLite. 8435** 8436** ^The current value of the requested parameter is written into *pCur 8437** and the highest instantaneous value is written into *pHiwtr. ^If 8438** the resetFlg is true, then the highest instantaneous value is 8439** reset back down to the current value. 8440** 8441** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 8442** non-zero [error code] on failure. 8443** 8444** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 8445*/ 8446SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 8447 8448/* 8449** CAPI3REF: Status Parameters for database connections 8450** KEYWORDS: {SQLITE_DBSTATUS options} 8451** 8452** These constants are the available integer "verbs" that can be passed as 8453** the second argument to the [sqlite3_db_status()] interface. 8454** 8455** New verbs may be added in future releases of SQLite. Existing verbs 8456** might be discontinued. Applications should check the return code from 8457** [sqlite3_db_status()] to make sure that the call worked. 8458** The [sqlite3_db_status()] interface will return a non-zero error code 8459** if a discontinued or unsupported verb is invoked. 8460** 8461** <dl> 8462** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 8463** <dd>This parameter returns the number of lookaside memory slots currently 8464** checked out.</dd>)^ 8465** 8466** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 8467** <dd>This parameter returns the number of malloc attempts that were 8468** satisfied using lookaside memory. Only the high-water value is meaningful; 8469** the current value is always zero.)^ 8470** 8471** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 8472** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 8473** <dd>This parameter returns the number malloc attempts that might have 8474** been satisfied using lookaside memory but failed due to the amount of 8475** memory requested being larger than the lookaside slot size. 8476** Only the high-water value is meaningful; 8477** the current value is always zero.)^ 8478** 8479** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 8480** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 8481** <dd>This parameter returns the number malloc attempts that might have 8482** been satisfied using lookaside memory but failed due to all lookaside 8483** memory already being in use. 8484** Only the high-water value is meaningful; 8485** the current value is always zero.)^ 8486** 8487** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 8488** <dd>This parameter returns the approximate number of bytes of heap 8489** memory used by all pager caches associated with the database connection.)^ 8490** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 8491** 8492** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 8493** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 8494** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 8495** pager cache is shared between two or more connections the bytes of heap 8496** memory used by that pager cache is divided evenly between the attached 8497** connections.)^ In other words, if none of the pager caches associated 8498** with the database connection are shared, this request returns the same 8499** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 8500** shared, the value returned by this call will be smaller than that returned 8501** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 8502** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 8503** 8504** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 8505** <dd>This parameter returns the approximate number of bytes of heap 8506** memory used to store the schema for all databases associated 8507** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 8508** ^The full amount of memory used by the schemas is reported, even if the 8509** schema memory is shared with other database connections due to 8510** [shared cache mode] being enabled. 8511** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 8512** 8513** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 8514** <dd>This parameter returns the approximate number of bytes of heap 8515** and lookaside memory used by all prepared statements associated with 8516** the database connection.)^ 8517** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 8518** </dd> 8519** 8520** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 8521** <dd>This parameter returns the number of pager cache hits that have 8522** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 8523** is always 0. 8524** </dd> 8525** 8526** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 8527** <dd>This parameter returns the number of pager cache misses that have 8528** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 8529** is always 0. 8530** </dd> 8531** 8532** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 8533** <dd>This parameter returns the number of dirty cache entries that have 8534** been written to disk. Specifically, the number of pages written to the 8535** wal file in wal mode databases, or the number of pages written to the 8536** database file in rollback mode databases. Any pages written as part of 8537** transaction rollback or database recovery operations are not included. 8538** If an IO or other error occurs while writing a page to disk, the effect 8539** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 8540** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 8541** </dd> 8542** 8543** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt> 8544** <dd>This parameter returns the number of dirty cache entries that have 8545** been written to disk in the middle of a transaction due to the page 8546** cache overflowing. Transactions are more efficient if they are written 8547** to disk all at once. When pages spill mid-transaction, that introduces 8548** additional overhead. This parameter can be used help identify 8549** inefficiencies that can be resolved by increasing the cache size. 8550** </dd> 8551** 8552** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 8553** <dd>This parameter returns zero for the current value if and only if 8554** all foreign key constraints (deferred or immediate) have been 8555** resolved.)^ ^The highwater mark is always 0. 8556** </dd> 8557** </dl> 8558*/ 8559#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 8560#define SQLITE_DBSTATUS_CACHE_USED 1 8561#define SQLITE_DBSTATUS_SCHEMA_USED 2 8562#define SQLITE_DBSTATUS_STMT_USED 3 8563#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 8564#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 8565#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 8566#define SQLITE_DBSTATUS_CACHE_HIT 7 8567#define SQLITE_DBSTATUS_CACHE_MISS 8 8568#define SQLITE_DBSTATUS_CACHE_WRITE 9 8569#define SQLITE_DBSTATUS_DEFERRED_FKS 10 8570#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 8571#define SQLITE_DBSTATUS_CACHE_SPILL 12 8572#define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */ 8573 8574 8575/* 8576** CAPI3REF: Prepared Statement Status 8577** METHOD: sqlite3_stmt 8578** 8579** ^(Each prepared statement maintains various 8580** [SQLITE_STMTSTATUS counters] that measure the number 8581** of times it has performed specific operations.)^ These counters can 8582** be used to monitor the performance characteristics of the prepared 8583** statements. For example, if the number of table steps greatly exceeds 8584** the number of table searches or result rows, that would tend to indicate 8585** that the prepared statement is using a full table scan rather than 8586** an index. 8587** 8588** ^(This interface is used to retrieve and reset counter values from 8589** a [prepared statement]. The first argument is the prepared statement 8590** object to be interrogated. The second argument 8591** is an integer code for a specific [SQLITE_STMTSTATUS counter] 8592** to be interrogated.)^ 8593** ^The current value of the requested counter is returned. 8594** ^If the resetFlg is true, then the counter is reset to zero after this 8595** interface call returns. 8596** 8597** See also: [sqlite3_status()] and [sqlite3_db_status()]. 8598*/ 8599SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 8600 8601/* 8602** CAPI3REF: Status Parameters for prepared statements 8603** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 8604** 8605** These preprocessor macros define integer codes that name counter 8606** values associated with the [sqlite3_stmt_status()] interface. 8607** The meanings of the various counters are as follows: 8608** 8609** <dl> 8610** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 8611** <dd>^This is the number of times that SQLite has stepped forward in 8612** a table as part of a full table scan. Large numbers for this counter 8613** may indicate opportunities for performance improvement through 8614** careful use of indices.</dd> 8615** 8616** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 8617** <dd>^This is the number of sort operations that have occurred. 8618** A non-zero value in this counter may indicate an opportunity to 8619** improvement performance through careful use of indices.</dd> 8620** 8621** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 8622** <dd>^This is the number of rows inserted into transient indices that 8623** were created automatically in order to help joins run faster. 8624** A non-zero value in this counter may indicate an opportunity to 8625** improvement performance by adding permanent indices that do not 8626** need to be reinitialized each time the statement is run.</dd> 8627** 8628** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 8629** <dd>^This is the number of virtual machine operations executed 8630** by the prepared statement if that number is less than or equal 8631** to 2147483647. The number of virtual machine operations can be 8632** used as a proxy for the total work done by the prepared statement. 8633** If the number of virtual machine operations exceeds 2147483647 8634** then the value returned by this statement status code is undefined. 8635** 8636** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> 8637** <dd>^This is the number of times that the prepare statement has been 8638** automatically regenerated due to schema changes or changes to 8639** [bound parameters] that might affect the query plan. 8640** 8641** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> 8642** <dd>^This is the number of times that the prepared statement has 8643** been run. A single "run" for the purposes of this counter is one 8644** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. 8645** The counter is incremented on the first [sqlite3_step()] call of each 8646** cycle. 8647** 8648** [[SQLITE_STMTSTATUS_FILTER_MISS]] 8649** [[SQLITE_STMTSTATUS_FILTER HIT]] 8650** <dt>SQLITE_STMTSTATUS_FILTER_HIT<br> 8651** SQLITE_STMTSTATUS_FILTER_MISS</dt> 8652** <dd>^SQLITE_STMTSTATUS_FILTER_HIT is the number of times that a join 8653** step was bypassed because a Bloom filter returned not-found. The 8654** corresponding SQLITE_STMTSTATUS_FILTER_MISS value is the number of 8655** times that the Bloom filter returned a find, and thus the join step 8656** had to be processed as normal. 8657** 8658** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> 8659** <dd>^This is the approximate number of bytes of heap memory 8660** used to store the prepared statement. ^This value is not actually 8661** a counter, and so the resetFlg parameter to sqlite3_stmt_status() 8662** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. 8663** </dd> 8664** </dl> 8665*/ 8666#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 8667#define SQLITE_STMTSTATUS_SORT 2 8668#define SQLITE_STMTSTATUS_AUTOINDEX 3 8669#define SQLITE_STMTSTATUS_VM_STEP 4 8670#define SQLITE_STMTSTATUS_REPREPARE 5 8671#define SQLITE_STMTSTATUS_RUN 6 8672#define SQLITE_STMTSTATUS_FILTER_MISS 7 8673#define SQLITE_STMTSTATUS_FILTER_HIT 8 8674#define SQLITE_STMTSTATUS_MEMUSED 99 8675 8676/* 8677** CAPI3REF: Custom Page Cache Object 8678** 8679** The sqlite3_pcache type is opaque. It is implemented by 8680** the pluggable module. The SQLite core has no knowledge of 8681** its size or internal structure and never deals with the 8682** sqlite3_pcache object except by holding and passing pointers 8683** to the object. 8684** 8685** See [sqlite3_pcache_methods2] for additional information. 8686*/ 8687typedef struct sqlite3_pcache sqlite3_pcache; 8688 8689/* 8690** CAPI3REF: Custom Page Cache Object 8691** 8692** The sqlite3_pcache_page object represents a single page in the 8693** page cache. The page cache will allocate instances of this 8694** object. Various methods of the page cache use pointers to instances 8695** of this object as parameters or as their return value. 8696** 8697** See [sqlite3_pcache_methods2] for additional information. 8698*/ 8699typedef struct sqlite3_pcache_page sqlite3_pcache_page; 8700struct sqlite3_pcache_page { 8701 void *pBuf; /* The content of the page */ 8702 void *pExtra; /* Extra information associated with the page */ 8703}; 8704 8705/* 8706** CAPI3REF: Application Defined Page Cache. 8707** KEYWORDS: {page cache} 8708** 8709** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 8710** register an alternative page cache implementation by passing in an 8711** instance of the sqlite3_pcache_methods2 structure.)^ 8712** In many applications, most of the heap memory allocated by 8713** SQLite is used for the page cache. 8714** By implementing a 8715** custom page cache using this API, an application can better control 8716** the amount of memory consumed by SQLite, the way in which 8717** that memory is allocated and released, and the policies used to 8718** determine exactly which parts of a database file are cached and for 8719** how long. 8720** 8721** The alternative page cache mechanism is an 8722** extreme measure that is only needed by the most demanding applications. 8723** The built-in page cache is recommended for most uses. 8724** 8725** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 8726** internal buffer by SQLite within the call to [sqlite3_config]. Hence 8727** the application may discard the parameter after the call to 8728** [sqlite3_config()] returns.)^ 8729** 8730** [[the xInit() page cache method]] 8731** ^(The xInit() method is called once for each effective 8732** call to [sqlite3_initialize()])^ 8733** (usually only once during the lifetime of the process). ^(The xInit() 8734** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 8735** The intent of the xInit() method is to set up global data structures 8736** required by the custom page cache implementation. 8737** ^(If the xInit() method is NULL, then the 8738** built-in default page cache is used instead of the application defined 8739** page cache.)^ 8740** 8741** [[the xShutdown() page cache method]] 8742** ^The xShutdown() method is called by [sqlite3_shutdown()]. 8743** It can be used to clean up 8744** any outstanding resources before process shutdown, if required. 8745** ^The xShutdown() method may be NULL. 8746** 8747** ^SQLite automatically serializes calls to the xInit method, 8748** so the xInit method need not be threadsafe. ^The 8749** xShutdown method is only called from [sqlite3_shutdown()] so it does 8750** not need to be threadsafe either. All other methods must be threadsafe 8751** in multithreaded applications. 8752** 8753** ^SQLite will never invoke xInit() more than once without an intervening 8754** call to xShutdown(). 8755** 8756** [[the xCreate() page cache methods]] 8757** ^SQLite invokes the xCreate() method to construct a new cache instance. 8758** SQLite will typically create one cache instance for each open database file, 8759** though this is not guaranteed. ^The 8760** first parameter, szPage, is the size in bytes of the pages that must 8761** be allocated by the cache. ^szPage will always a power of two. ^The 8762** second parameter szExtra is a number of bytes of extra storage 8763** associated with each page cache entry. ^The szExtra parameter will 8764** a number less than 250. SQLite will use the 8765** extra szExtra bytes on each page to store metadata about the underlying 8766** database page on disk. The value passed into szExtra depends 8767** on the SQLite version, the target platform, and how SQLite was compiled. 8768** ^The third argument to xCreate(), bPurgeable, is true if the cache being 8769** created will be used to cache database pages of a file stored on disk, or 8770** false if it is used for an in-memory database. The cache implementation 8771** does not have to do anything special based with the value of bPurgeable; 8772** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 8773** never invoke xUnpin() except to deliberately delete a page. 8774** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 8775** false will always have the "discard" flag set to true. 8776** ^Hence, a cache created with bPurgeable false will 8777** never contain any unpinned pages. 8778** 8779** [[the xCachesize() page cache method]] 8780** ^(The xCachesize() method may be called at any time by SQLite to set the 8781** suggested maximum cache-size (number of pages stored by) the cache 8782** instance passed as the first argument. This is the value configured using 8783** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 8784** parameter, the implementation is not required to do anything with this 8785** value; it is advisory only. 8786** 8787** [[the xPagecount() page cache methods]] 8788** The xPagecount() method must return the number of pages currently 8789** stored in the cache, both pinned and unpinned. 8790** 8791** [[the xFetch() page cache methods]] 8792** The xFetch() method locates a page in the cache and returns a pointer to 8793** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 8794** The pBuf element of the returned sqlite3_pcache_page object will be a 8795** pointer to a buffer of szPage bytes used to store the content of a 8796** single database page. The pExtra element of sqlite3_pcache_page will be 8797** a pointer to the szExtra bytes of extra storage that SQLite has requested 8798** for each entry in the page cache. 8799** 8800** The page to be fetched is determined by the key. ^The minimum key value 8801** is 1. After it has been retrieved using xFetch, the page is considered 8802** to be "pinned". 8803** 8804** If the requested page is already in the page cache, then the page cache 8805** implementation must return a pointer to the page buffer with its content 8806** intact. If the requested page is not already in the cache, then the 8807** cache implementation should use the value of the createFlag 8808** parameter to help it determined what action to take: 8809** 8810** <table border=1 width=85% align=center> 8811** <tr><th> createFlag <th> Behavior when page is not already in cache 8812** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 8813** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 8814** Otherwise return NULL. 8815** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 8816** NULL if allocating a new page is effectively impossible. 8817** </table> 8818** 8819** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 8820** will only use a createFlag of 2 after a prior call with a createFlag of 1 8821** failed.)^ In between the xFetch() calls, SQLite may 8822** attempt to unpin one or more cache pages by spilling the content of 8823** pinned pages to disk and synching the operating system disk cache. 8824** 8825** [[the xUnpin() page cache method]] 8826** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 8827** as its second argument. If the third parameter, discard, is non-zero, 8828** then the page must be evicted from the cache. 8829** ^If the discard parameter is 8830** zero, then the page may be discarded or retained at the discretion of 8831** page cache implementation. ^The page cache implementation 8832** may choose to evict unpinned pages at any time. 8833** 8834** The cache must not perform any reference counting. A single 8835** call to xUnpin() unpins the page regardless of the number of prior calls 8836** to xFetch(). 8837** 8838** [[the xRekey() page cache methods]] 8839** The xRekey() method is used to change the key value associated with the 8840** page passed as the second argument. If the cache 8841** previously contains an entry associated with newKey, it must be 8842** discarded. ^Any prior cache entry associated with newKey is guaranteed not 8843** to be pinned. 8844** 8845** When SQLite calls the xTruncate() method, the cache must discard all 8846** existing cache entries with page numbers (keys) greater than or equal 8847** to the value of the iLimit parameter passed to xTruncate(). If any 8848** of these pages are pinned, they are implicitly unpinned, meaning that 8849** they can be safely discarded. 8850** 8851** [[the xDestroy() page cache method]] 8852** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 8853** All resources associated with the specified cache should be freed. ^After 8854** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 8855** handle invalid, and will not use it with any other sqlite3_pcache_methods2 8856** functions. 8857** 8858** [[the xShrink() page cache method]] 8859** ^SQLite invokes the xShrink() method when it wants the page cache to 8860** free up as much of heap memory as possible. The page cache implementation 8861** is not obligated to free any memory, but well-behaved implementations should 8862** do their best. 8863*/ 8864typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 8865struct sqlite3_pcache_methods2 { 8866 int iVersion; 8867 void *pArg; 8868 int (*xInit)(void*); 8869 void (*xShutdown)(void*); 8870 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 8871 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8872 int (*xPagecount)(sqlite3_pcache*); 8873 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8874 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 8875 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 8876 unsigned oldKey, unsigned newKey); 8877 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8878 void (*xDestroy)(sqlite3_pcache*); 8879 void (*xShrink)(sqlite3_pcache*); 8880}; 8881 8882/* 8883** This is the obsolete pcache_methods object that has now been replaced 8884** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 8885** retained in the header file for backwards compatibility only. 8886*/ 8887typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 8888struct sqlite3_pcache_methods { 8889 void *pArg; 8890 int (*xInit)(void*); 8891 void (*xShutdown)(void*); 8892 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 8893 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8894 int (*xPagecount)(sqlite3_pcache*); 8895 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8896 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 8897 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 8898 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8899 void (*xDestroy)(sqlite3_pcache*); 8900}; 8901 8902 8903/* 8904** CAPI3REF: Online Backup Object 8905** 8906** The sqlite3_backup object records state information about an ongoing 8907** online backup operation. ^The sqlite3_backup object is created by 8908** a call to [sqlite3_backup_init()] and is destroyed by a call to 8909** [sqlite3_backup_finish()]. 8910** 8911** See Also: [Using the SQLite Online Backup API] 8912*/ 8913typedef struct sqlite3_backup sqlite3_backup; 8914 8915/* 8916** CAPI3REF: Online Backup API. 8917** 8918** The backup API copies the content of one database into another. 8919** It is useful either for creating backups of databases or 8920** for copying in-memory databases to or from persistent files. 8921** 8922** See Also: [Using the SQLite Online Backup API] 8923** 8924** ^SQLite holds a write transaction open on the destination database file 8925** for the duration of the backup operation. 8926** ^The source database is read-locked only while it is being read; 8927** it is not locked continuously for the entire backup operation. 8928** ^Thus, the backup may be performed on a live source database without 8929** preventing other database connections from 8930** reading or writing to the source database while the backup is underway. 8931** 8932** ^(To perform a backup operation: 8933** <ol> 8934** <li><b>sqlite3_backup_init()</b> is called once to initialize the 8935** backup, 8936** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 8937** the data between the two databases, and finally 8938** <li><b>sqlite3_backup_finish()</b> is called to release all resources 8939** associated with the backup operation. 8940** </ol>)^ 8941** There should be exactly one call to sqlite3_backup_finish() for each 8942** successful call to sqlite3_backup_init(). 8943** 8944** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 8945** 8946** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 8947** [database connection] associated with the destination database 8948** and the database name, respectively. 8949** ^The database name is "main" for the main database, "temp" for the 8950** temporary database, or the name specified after the AS keyword in 8951** an [ATTACH] statement for an attached database. 8952** ^The S and M arguments passed to 8953** sqlite3_backup_init(D,N,S,M) identify the [database connection] 8954** and database name of the source database, respectively. 8955** ^The source and destination [database connections] (parameters S and D) 8956** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 8957** an error. 8958** 8959** ^A call to sqlite3_backup_init() will fail, returning NULL, if 8960** there is already a read or read-write transaction open on the 8961** destination database. 8962** 8963** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 8964** returned and an error code and error message are stored in the 8965** destination [database connection] D. 8966** ^The error code and message for the failed call to sqlite3_backup_init() 8967** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 8968** [sqlite3_errmsg16()] functions. 8969** ^A successful call to sqlite3_backup_init() returns a pointer to an 8970** [sqlite3_backup] object. 8971** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 8972** sqlite3_backup_finish() functions to perform the specified backup 8973** operation. 8974** 8975** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 8976** 8977** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 8978** the source and destination databases specified by [sqlite3_backup] object B. 8979** ^If N is negative, all remaining source pages are copied. 8980** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 8981** are still more pages to be copied, then the function returns [SQLITE_OK]. 8982** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 8983** from source to destination, then it returns [SQLITE_DONE]. 8984** ^If an error occurs while running sqlite3_backup_step(B,N), 8985** then an [error code] is returned. ^As well as [SQLITE_OK] and 8986** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 8987** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 8988** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 8989** 8990** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 8991** <ol> 8992** <li> the destination database was opened read-only, or 8993** <li> the destination database is using write-ahead-log journaling 8994** and the destination and source page sizes differ, or 8995** <li> the destination database is an in-memory database and the 8996** destination and source page sizes differ. 8997** </ol>)^ 8998** 8999** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 9000** the [sqlite3_busy_handler | busy-handler function] 9001** is invoked (if one is specified). ^If the 9002** busy-handler returns non-zero before the lock is available, then 9003** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 9004** sqlite3_backup_step() can be retried later. ^If the source 9005** [database connection] 9006** is being used to write to the source database when sqlite3_backup_step() 9007** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 9008** case the call to sqlite3_backup_step() can be retried later on. ^(If 9009** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 9010** [SQLITE_READONLY] is returned, then 9011** there is no point in retrying the call to sqlite3_backup_step(). These 9012** errors are considered fatal.)^ The application must accept 9013** that the backup operation has failed and pass the backup operation handle 9014** to the sqlite3_backup_finish() to release associated resources. 9015** 9016** ^The first call to sqlite3_backup_step() obtains an exclusive lock 9017** on the destination file. ^The exclusive lock is not released until either 9018** sqlite3_backup_finish() is called or the backup operation is complete 9019** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 9020** sqlite3_backup_step() obtains a [shared lock] on the source database that 9021** lasts for the duration of the sqlite3_backup_step() call. 9022** ^Because the source database is not locked between calls to 9023** sqlite3_backup_step(), the source database may be modified mid-way 9024** through the backup process. ^If the source database is modified by an 9025** external process or via a database connection other than the one being 9026** used by the backup operation, then the backup will be automatically 9027** restarted by the next call to sqlite3_backup_step(). ^If the source 9028** database is modified by the using the same database connection as is used 9029** by the backup operation, then the backup database is automatically 9030** updated at the same time. 9031** 9032** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 9033** 9034** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 9035** application wishes to abandon the backup operation, the application 9036** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 9037** ^The sqlite3_backup_finish() interfaces releases all 9038** resources associated with the [sqlite3_backup] object. 9039** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 9040** active write-transaction on the destination database is rolled back. 9041** The [sqlite3_backup] object is invalid 9042** and may not be used following a call to sqlite3_backup_finish(). 9043** 9044** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 9045** sqlite3_backup_step() errors occurred, regardless or whether or not 9046** sqlite3_backup_step() completed. 9047** ^If an out-of-memory condition or IO error occurred during any prior 9048** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 9049** sqlite3_backup_finish() returns the corresponding [error code]. 9050** 9051** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 9052** is not a permanent error and does not affect the return value of 9053** sqlite3_backup_finish(). 9054** 9055** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 9056** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 9057** 9058** ^The sqlite3_backup_remaining() routine returns the number of pages still 9059** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 9060** ^The sqlite3_backup_pagecount() routine returns the total number of pages 9061** in the source database at the conclusion of the most recent 9062** sqlite3_backup_step(). 9063** ^(The values returned by these functions are only updated by 9064** sqlite3_backup_step(). If the source database is modified in a way that 9065** changes the size of the source database or the number of pages remaining, 9066** those changes are not reflected in the output of sqlite3_backup_pagecount() 9067** and sqlite3_backup_remaining() until after the next 9068** sqlite3_backup_step().)^ 9069** 9070** <b>Concurrent Usage of Database Handles</b> 9071** 9072** ^The source [database connection] may be used by the application for other 9073** purposes while a backup operation is underway or being initialized. 9074** ^If SQLite is compiled and configured to support threadsafe database 9075** connections, then the source database connection may be used concurrently 9076** from within other threads. 9077** 9078** However, the application must guarantee that the destination 9079** [database connection] is not passed to any other API (by any thread) after 9080** sqlite3_backup_init() is called and before the corresponding call to 9081** sqlite3_backup_finish(). SQLite does not currently check to see 9082** if the application incorrectly accesses the destination [database connection] 9083** and so no error code is reported, but the operations may malfunction 9084** nevertheless. Use of the destination database connection while a 9085** backup is in progress might also cause a mutex deadlock. 9086** 9087** If running in [shared cache mode], the application must 9088** guarantee that the shared cache used by the destination database 9089** is not accessed while the backup is running. In practice this means 9090** that the application must guarantee that the disk file being 9091** backed up to is not accessed by any connection within the process, 9092** not just the specific connection that was passed to sqlite3_backup_init(). 9093** 9094** The [sqlite3_backup] object itself is partially threadsafe. Multiple 9095** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 9096** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 9097** APIs are not strictly speaking threadsafe. If they are invoked at the 9098** same time as another thread is invoking sqlite3_backup_step() it is 9099** possible that they return invalid values. 9100*/ 9101SQLITE_API sqlite3_backup *sqlite3_backup_init( 9102 sqlite3 *pDest, /* Destination database handle */ 9103 const char *zDestName, /* Destination database name */ 9104 sqlite3 *pSource, /* Source database handle */ 9105 const char *zSourceName /* Source database name */ 9106); 9107SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 9108SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 9109SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 9110SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 9111 9112/* 9113** CAPI3REF: Unlock Notification 9114** METHOD: sqlite3 9115** 9116** ^When running in shared-cache mode, a database operation may fail with 9117** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 9118** individual tables within the shared-cache cannot be obtained. See 9119** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 9120** ^This API may be used to register a callback that SQLite will invoke 9121** when the connection currently holding the required lock relinquishes it. 9122** ^This API is only available if the library was compiled with the 9123** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 9124** 9125** See Also: [Using the SQLite Unlock Notification Feature]. 9126** 9127** ^Shared-cache locks are released when a database connection concludes 9128** its current transaction, either by committing it or rolling it back. 9129** 9130** ^When a connection (known as the blocked connection) fails to obtain a 9131** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 9132** identity of the database connection (the blocking connection) that 9133** has locked the required resource is stored internally. ^After an 9134** application receives an SQLITE_LOCKED error, it may call the 9135** sqlite3_unlock_notify() method with the blocked connection handle as 9136** the first argument to register for a callback that will be invoked 9137** when the blocking connections current transaction is concluded. ^The 9138** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 9139** call that concludes the blocking connection's transaction. 9140** 9141** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 9142** there is a chance that the blocking connection will have already 9143** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 9144** If this happens, then the specified callback is invoked immediately, 9145** from within the call to sqlite3_unlock_notify().)^ 9146** 9147** ^If the blocked connection is attempting to obtain a write-lock on a 9148** shared-cache table, and more than one other connection currently holds 9149** a read-lock on the same table, then SQLite arbitrarily selects one of 9150** the other connections to use as the blocking connection. 9151** 9152** ^(There may be at most one unlock-notify callback registered by a 9153** blocked connection. If sqlite3_unlock_notify() is called when the 9154** blocked connection already has a registered unlock-notify callback, 9155** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 9156** called with a NULL pointer as its second argument, then any existing 9157** unlock-notify callback is canceled. ^The blocked connections 9158** unlock-notify callback may also be canceled by closing the blocked 9159** connection using [sqlite3_close()]. 9160** 9161** The unlock-notify callback is not reentrant. If an application invokes 9162** any sqlite3_xxx API functions from within an unlock-notify callback, a 9163** crash or deadlock may be the result. 9164** 9165** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 9166** returns SQLITE_OK. 9167** 9168** <b>Callback Invocation Details</b> 9169** 9170** When an unlock-notify callback is registered, the application provides a 9171** single void* pointer that is passed to the callback when it is invoked. 9172** However, the signature of the callback function allows SQLite to pass 9173** it an array of void* context pointers. The first argument passed to 9174** an unlock-notify callback is a pointer to an array of void* pointers, 9175** and the second is the number of entries in the array. 9176** 9177** When a blocking connection's transaction is concluded, there may be 9178** more than one blocked connection that has registered for an unlock-notify 9179** callback. ^If two or more such blocked connections have specified the 9180** same callback function, then instead of invoking the callback function 9181** multiple times, it is invoked once with the set of void* context pointers 9182** specified by the blocked connections bundled together into an array. 9183** This gives the application an opportunity to prioritize any actions 9184** related to the set of unblocked database connections. 9185** 9186** <b>Deadlock Detection</b> 9187** 9188** Assuming that after registering for an unlock-notify callback a 9189** database waits for the callback to be issued before taking any further 9190** action (a reasonable assumption), then using this API may cause the 9191** application to deadlock. For example, if connection X is waiting for 9192** connection Y's transaction to be concluded, and similarly connection 9193** Y is waiting on connection X's transaction, then neither connection 9194** will proceed and the system may remain deadlocked indefinitely. 9195** 9196** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 9197** detection. ^If a given call to sqlite3_unlock_notify() would put the 9198** system in a deadlocked state, then SQLITE_LOCKED is returned and no 9199** unlock-notify callback is registered. The system is said to be in 9200** a deadlocked state if connection A has registered for an unlock-notify 9201** callback on the conclusion of connection B's transaction, and connection 9202** B has itself registered for an unlock-notify callback when connection 9203** A's transaction is concluded. ^Indirect deadlock is also detected, so 9204** the system is also considered to be deadlocked if connection B has 9205** registered for an unlock-notify callback on the conclusion of connection 9206** C's transaction, where connection C is waiting on connection A. ^Any 9207** number of levels of indirection are allowed. 9208** 9209** <b>The "DROP TABLE" Exception</b> 9210** 9211** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 9212** always appropriate to call sqlite3_unlock_notify(). There is however, 9213** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 9214** SQLite checks if there are any currently executing SELECT statements 9215** that belong to the same connection. If there are, SQLITE_LOCKED is 9216** returned. In this case there is no "blocking connection", so invoking 9217** sqlite3_unlock_notify() results in the unlock-notify callback being 9218** invoked immediately. If the application then re-attempts the "DROP TABLE" 9219** or "DROP INDEX" query, an infinite loop might be the result. 9220** 9221** One way around this problem is to check the extended error code returned 9222** by an sqlite3_step() call. ^(If there is a blocking connection, then the 9223** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 9224** the special "DROP TABLE/INDEX" case, the extended error code is just 9225** SQLITE_LOCKED.)^ 9226*/ 9227SQLITE_API int sqlite3_unlock_notify( 9228 sqlite3 *pBlocked, /* Waiting connection */ 9229 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 9230 void *pNotifyArg /* Argument to pass to xNotify */ 9231); 9232 9233 9234/* 9235** CAPI3REF: String Comparison 9236** 9237** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 9238** and extensions to compare the contents of two buffers containing UTF-8 9239** strings in a case-independent fashion, using the same definition of "case 9240** independence" that SQLite uses internally when comparing identifiers. 9241*/ 9242SQLITE_API int sqlite3_stricmp(const char *, const char *); 9243SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 9244 9245/* 9246** CAPI3REF: String Globbing 9247* 9248** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 9249** string X matches the [GLOB] pattern P. 9250** ^The definition of [GLOB] pattern matching used in 9251** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 9252** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 9253** is case sensitive. 9254** 9255** Note that this routine returns zero on a match and non-zero if the strings 9256** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 9257** 9258** See also: [sqlite3_strlike()]. 9259*/ 9260SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr); 9261 9262/* 9263** CAPI3REF: String LIKE Matching 9264* 9265** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 9266** string X matches the [LIKE] pattern P with escape character E. 9267** ^The definition of [LIKE] pattern matching used in 9268** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 9269** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 9270** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 9271** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 9272** insensitive - equivalent upper and lower case ASCII characters match 9273** one another. 9274** 9275** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 9276** only ASCII characters are case folded. 9277** 9278** Note that this routine returns zero on a match and non-zero if the strings 9279** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 9280** 9281** See also: [sqlite3_strglob()]. 9282*/ 9283SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 9284 9285/* 9286** CAPI3REF: Error Logging Interface 9287** 9288** ^The [sqlite3_log()] interface writes a message into the [error log] 9289** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 9290** ^If logging is enabled, the zFormat string and subsequent arguments are 9291** used with [sqlite3_snprintf()] to generate the final output string. 9292** 9293** The sqlite3_log() interface is intended for use by extensions such as 9294** virtual tables, collating functions, and SQL functions. While there is 9295** nothing to prevent an application from calling sqlite3_log(), doing so 9296** is considered bad form. 9297** 9298** The zFormat string must not be NULL. 9299** 9300** To avoid deadlocks and other threading problems, the sqlite3_log() routine 9301** will not use dynamically allocated memory. The log message is stored in 9302** a fixed-length buffer on the stack. If the log message is longer than 9303** a few hundred characters, it will be truncated to the length of the 9304** buffer. 9305*/ 9306SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 9307 9308/* 9309** CAPI3REF: Write-Ahead Log Commit Hook 9310** METHOD: sqlite3 9311** 9312** ^The [sqlite3_wal_hook()] function is used to register a callback that 9313** is invoked each time data is committed to a database in wal mode. 9314** 9315** ^(The callback is invoked by SQLite after the commit has taken place and 9316** the associated write-lock on the database released)^, so the implementation 9317** may read, write or [checkpoint] the database as required. 9318** 9319** ^The first parameter passed to the callback function when it is invoked 9320** is a copy of the third parameter passed to sqlite3_wal_hook() when 9321** registering the callback. ^The second is a copy of the database handle. 9322** ^The third parameter is the name of the database that was written to - 9323** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 9324** is the number of pages currently in the write-ahead log file, 9325** including those that were just committed. 9326** 9327** The callback function should normally return [SQLITE_OK]. ^If an error 9328** code is returned, that error will propagate back up through the 9329** SQLite code base to cause the statement that provoked the callback 9330** to report an error, though the commit will have still occurred. If the 9331** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 9332** that does not correspond to any valid SQLite error code, the results 9333** are undefined. 9334** 9335** A single database handle may have at most a single write-ahead log callback 9336** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 9337** previously registered write-ahead log callback. ^The return value is 9338** a copy of the third parameter from the previous call, if any, or 0. 9339** ^Note that the [sqlite3_wal_autocheckpoint()] interface and the 9340** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 9341** overwrite any prior [sqlite3_wal_hook()] settings. 9342*/ 9343SQLITE_API void *sqlite3_wal_hook( 9344 sqlite3*, 9345 int(*)(void *,sqlite3*,const char*,int), 9346 void* 9347); 9348 9349/* 9350** CAPI3REF: Configure an auto-checkpoint 9351** METHOD: sqlite3 9352** 9353** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 9354** [sqlite3_wal_hook()] that causes any database on [database connection] D 9355** to automatically [checkpoint] 9356** after committing a transaction if there are N or 9357** more frames in the [write-ahead log] file. ^Passing zero or 9358** a negative value as the nFrame parameter disables automatic 9359** checkpoints entirely. 9360** 9361** ^The callback registered by this function replaces any existing callback 9362** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 9363** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 9364** configured by this function. 9365** 9366** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 9367** from SQL. 9368** 9369** ^Checkpoints initiated by this mechanism are 9370** [sqlite3_wal_checkpoint_v2|PASSIVE]. 9371** 9372** ^Every new [database connection] defaults to having the auto-checkpoint 9373** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 9374** pages. The use of this interface 9375** is only necessary if the default setting is found to be suboptimal 9376** for a particular application. 9377*/ 9378SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 9379 9380/* 9381** CAPI3REF: Checkpoint a database 9382** METHOD: sqlite3 9383** 9384** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 9385** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 9386** 9387** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 9388** [write-ahead log] for database X on [database connection] D to be 9389** transferred into the database file and for the write-ahead log to 9390** be reset. See the [checkpointing] documentation for addition 9391** information. 9392** 9393** This interface used to be the only way to cause a checkpoint to 9394** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 9395** interface was added. This interface is retained for backwards 9396** compatibility and as a convenience for applications that need to manually 9397** start a callback but which do not need the full power (and corresponding 9398** complication) of [sqlite3_wal_checkpoint_v2()]. 9399*/ 9400SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 9401 9402/* 9403** CAPI3REF: Checkpoint a database 9404** METHOD: sqlite3 9405** 9406** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 9407** operation on database X of [database connection] D in mode M. Status 9408** information is written back into integers pointed to by L and C.)^ 9409** ^(The M parameter must be a valid [checkpoint mode]:)^ 9410** 9411** <dl> 9412** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 9413** ^Checkpoint as many frames as possible without waiting for any database 9414** readers or writers to finish, then sync the database file if all frames 9415** in the log were checkpointed. ^The [busy-handler callback] 9416** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 9417** ^On the other hand, passive mode might leave the checkpoint unfinished 9418** if there are concurrent readers or writers. 9419** 9420** <dt>SQLITE_CHECKPOINT_FULL<dd> 9421** ^This mode blocks (it invokes the 9422** [sqlite3_busy_handler|busy-handler callback]) until there is no 9423** database writer and all readers are reading from the most recent database 9424** snapshot. ^It then checkpoints all frames in the log file and syncs the 9425** database file. ^This mode blocks new database writers while it is pending, 9426** but new database readers are allowed to continue unimpeded. 9427** 9428** <dt>SQLITE_CHECKPOINT_RESTART<dd> 9429** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 9430** that after checkpointing the log file it blocks (calls the 9431** [busy-handler callback]) 9432** until all readers are reading from the database file only. ^This ensures 9433** that the next writer will restart the log file from the beginning. 9434** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 9435** database writer attempts while it is pending, but does not impede readers. 9436** 9437** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 9438** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 9439** addition that it also truncates the log file to zero bytes just prior 9440** to a successful return. 9441** </dl> 9442** 9443** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 9444** the log file or to -1 if the checkpoint could not run because 9445** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 9446** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 9447** log file (including any that were already checkpointed before the function 9448** was called) or to -1 if the checkpoint could not run due to an error or 9449** because the database is not in WAL mode. ^Note that upon successful 9450** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 9451** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 9452** 9453** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 9454** any other process is running a checkpoint operation at the same time, the 9455** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 9456** busy-handler configured, it will not be invoked in this case. 9457** 9458** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 9459** exclusive "writer" lock on the database file. ^If the writer lock cannot be 9460** obtained immediately, and a busy-handler is configured, it is invoked and 9461** the writer lock retried until either the busy-handler returns 0 or the lock 9462** is successfully obtained. ^The busy-handler is also invoked while waiting for 9463** database readers as described above. ^If the busy-handler returns 0 before 9464** the writer lock is obtained or while waiting for database readers, the 9465** checkpoint operation proceeds from that point in the same way as 9466** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 9467** without blocking any further. ^SQLITE_BUSY is returned in this case. 9468** 9469** ^If parameter zDb is NULL or points to a zero length string, then the 9470** specified operation is attempted on all WAL databases [attached] to 9471** [database connection] db. In this case the 9472** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 9473** an SQLITE_BUSY error is encountered when processing one or more of the 9474** attached WAL databases, the operation is still attempted on any remaining 9475** attached databases and SQLITE_BUSY is returned at the end. ^If any other 9476** error occurs while processing an attached database, processing is abandoned 9477** and the error code is returned to the caller immediately. ^If no error 9478** (SQLITE_BUSY or otherwise) is encountered while processing the attached 9479** databases, SQLITE_OK is returned. 9480** 9481** ^If database zDb is the name of an attached database that is not in WAL 9482** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 9483** zDb is not NULL (or a zero length string) and is not the name of any 9484** attached database, SQLITE_ERROR is returned to the caller. 9485** 9486** ^Unless it returns SQLITE_MISUSE, 9487** the sqlite3_wal_checkpoint_v2() interface 9488** sets the error information that is queried by 9489** [sqlite3_errcode()] and [sqlite3_errmsg()]. 9490** 9491** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 9492** from SQL. 9493*/ 9494SQLITE_API int sqlite3_wal_checkpoint_v2( 9495 sqlite3 *db, /* Database handle */ 9496 const char *zDb, /* Name of attached database (or NULL) */ 9497 int eMode, /* SQLITE_CHECKPOINT_* value */ 9498 int *pnLog, /* OUT: Size of WAL log in frames */ 9499 int *pnCkpt /* OUT: Total number of frames checkpointed */ 9500); 9501 9502/* 9503** CAPI3REF: Checkpoint Mode Values 9504** KEYWORDS: {checkpoint mode} 9505** 9506** These constants define all valid values for the "checkpoint mode" passed 9507** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 9508** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 9509** meaning of each of these checkpoint modes. 9510*/ 9511#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 9512#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 9513#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for readers */ 9514#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 9515 9516/* 9517** CAPI3REF: Virtual Table Interface Configuration 9518** 9519** This function may be called by either the [xConnect] or [xCreate] method 9520** of a [virtual table] implementation to configure 9521** various facets of the virtual table interface. 9522** 9523** If this interface is invoked outside the context of an xConnect or 9524** xCreate virtual table method then the behavior is undefined. 9525** 9526** In the call sqlite3_vtab_config(D,C,...) the D parameter is the 9527** [database connection] in which the virtual table is being created and 9528** which is passed in as the first argument to the [xConnect] or [xCreate] 9529** method that is invoking sqlite3_vtab_config(). The C parameter is one 9530** of the [virtual table configuration options]. The presence and meaning 9531** of parameters after C depend on which [virtual table configuration option] 9532** is used. 9533*/ 9534SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); 9535 9536/* 9537** CAPI3REF: Virtual Table Configuration Options 9538** KEYWORDS: {virtual table configuration options} 9539** KEYWORDS: {virtual table configuration option} 9540** 9541** These macros define the various options to the 9542** [sqlite3_vtab_config()] interface that [virtual table] implementations 9543** can use to customize and optimize their behavior. 9544** 9545** <dl> 9546** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]] 9547** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt> 9548** <dd>Calls of the form 9549** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 9550** where X is an integer. If X is zero, then the [virtual table] whose 9551** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 9552** support constraints. In this configuration (which is the default) if 9553** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 9554** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 9555** specified as part of the users SQL statement, regardless of the actual 9556** ON CONFLICT mode specified. 9557** 9558** If X is non-zero, then the virtual table implementation guarantees 9559** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 9560** any modifications to internal or persistent data structures have been made. 9561** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 9562** is able to roll back a statement or database transaction, and abandon 9563** or continue processing the current SQL statement as appropriate. 9564** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 9565** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 9566** had been ABORT. 9567** 9568** Virtual table implementations that are required to handle OR REPLACE 9569** must do so within the [xUpdate] method. If a call to the 9570** [sqlite3_vtab_on_conflict()] function indicates that the current ON 9571** CONFLICT policy is REPLACE, the virtual table implementation should 9572** silently replace the appropriate rows within the xUpdate callback and 9573** return SQLITE_OK. Or, if this is not possible, it may return 9574** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 9575** constraint handling. 9576** </dd> 9577** 9578** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt> 9579** <dd>Calls of the form 9580** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the 9581** the [xConnect] or [xCreate] methods of a [virtual table] implmentation 9582** prohibits that virtual table from being used from within triggers and 9583** views. 9584** </dd> 9585** 9586** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt> 9587** <dd>Calls of the form 9588** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the 9589** the [xConnect] or [xCreate] methods of a [virtual table] implmentation 9590** identify that virtual table as being safe to use from within triggers 9591** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the 9592** virtual table can do no serious harm even if it is controlled by a 9593** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS 9594** flag unless absolutely necessary. 9595** </dd> 9596** </dl> 9597*/ 9598#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 9599#define SQLITE_VTAB_INNOCUOUS 2 9600#define SQLITE_VTAB_DIRECTONLY 3 9601 9602/* 9603** CAPI3REF: Determine The Virtual Table Conflict Policy 9604** 9605** This function may only be called from within a call to the [xUpdate] method 9606** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 9607** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 9608** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 9609** of the SQL statement that triggered the call to the [xUpdate] method of the 9610** [virtual table]. 9611*/ 9612SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); 9613 9614/* 9615** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE 9616** 9617** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn] 9618** method of a [virtual table], then it might return true if the 9619** column is being fetched as part of an UPDATE operation during which the 9620** column value will not change. The virtual table implementation can use 9621** this hint as permission to substitute a return value that is less 9622** expensive to compute and that the corresponding 9623** [xUpdate] method understands as a "no-change" value. 9624** 9625** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that 9626** the column is not changed by the UPDATE statement, then the xColumn 9627** method can optionally return without setting a result, without calling 9628** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces]. 9629** In that case, [sqlite3_value_nochange(X)] will return true for the 9630** same column in the [xUpdate] method. 9631** 9632** The sqlite3_vtab_nochange() routine is an optimization. Virtual table 9633** implementations should continue to give a correct answer even if the 9634** sqlite3_vtab_nochange() interface were to always return false. In the 9635** current implementation, the sqlite3_vtab_nochange() interface does always 9636** returns false for the enhanced [UPDATE FROM] statement. 9637*/ 9638SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*); 9639 9640/* 9641** CAPI3REF: Determine The Collation For a Virtual Table Constraint 9642** METHOD: sqlite3_index_info 9643** 9644** This function may only be called from within a call to the [xBestIndex] 9645** method of a [virtual table]. This function returns a pointer to a string 9646** that is the name of the appropriate collation sequence to use for text 9647** comparisons on the constraint identified by its arguments. 9648** 9649** The first argument must be the pointer to the [sqlite3_index_info] object 9650** that is the first parameter to the xBestIndex() method. The second argument 9651** must be an index into the aConstraint[] array belonging to the 9652** sqlite3_index_info structure passed to xBestIndex. 9653** 9654** Important: 9655** The first parameter must be the same pointer that is passed into the 9656** xBestMethod() method. The first parameter may not be a pointer to a 9657** different [sqlite3_index_info] object, even an exact copy. 9658** 9659** The return value is computed as follows: 9660** 9661** <ol> 9662** <li><p> If the constraint comes from a WHERE clause expression that contains 9663** a [COLLATE operator], then the name of the collation specified by 9664** that COLLATE operator is returned. 9665** <li><p> If there is no COLLATE operator, but the column that is the subject 9666** of the constraint specifies an alternative collating sequence via 9667** a [COLLATE clause] on the column definition within the CREATE TABLE 9668** statement that was passed into [sqlite3_declare_vtab()], then the 9669** name of that alternative collating sequence is returned. 9670** <li><p> Otherwise, "BINARY" is returned. 9671** </ol> 9672*/ 9673SQLITE_API SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int); 9674 9675/* 9676** CAPI3REF: Determine if a virtual table query is DISTINCT 9677** METHOD: sqlite3_index_info 9678** 9679** This API may only be used from within an [xBestIndex|xBestIndex method] 9680** of a [virtual table] implementation. The result of calling this 9681** interface from outside of xBestIndex() is undefined and probably harmful. 9682** 9683** ^The sqlite3_vtab_distinct() interface returns an integer between 0 and 9684** 3. The integer returned by sqlite3_vtab_distinct() 9685** gives the virtual table additional information about how the query 9686** planner wants the output to be ordered. As long as the virtual table 9687** can meet the ordering requirements of the query planner, it may set 9688** the "orderByConsumed" flag. 9689** 9690** <ol><li value="0"><p> 9691** ^If the sqlite3_vtab_distinct() interface returns 0, that means 9692** that the query planner needs the virtual table to return all rows in the 9693** sort order defined by the "nOrderBy" and "aOrderBy" fields of the 9694** [sqlite3_index_info] object. This is the default expectation. If the 9695** virtual table outputs all rows in sorted order, then it is always safe for 9696** the xBestIndex method to set the "orderByConsumed" flag, regardless of 9697** the return value from sqlite3_vtab_distinct(). 9698** <li value="1"><p> 9699** ^(If the sqlite3_vtab_distinct() interface returns 1, that means 9700** that the query planner does not need the rows to be returned in sorted order 9701** as long as all rows with the same values in all columns identified by the 9702** "aOrderBy" field are adjacent.)^ This mode is used when the query planner 9703** is doing a GROUP BY. 9704** <li value="2"><p> 9705** ^(If the sqlite3_vtab_distinct() interface returns 2, that means 9706** that the query planner does not need the rows returned in any particular 9707** order, as long as rows with the same values in all "aOrderBy" columns 9708** are adjacent.)^ ^(Furthermore, only a single row for each particular 9709** combination of values in the columns identified by the "aOrderBy" field 9710** needs to be returned.)^ ^It is always ok for two or more rows with the same 9711** values in all "aOrderBy" columns to be returned, as long as all such rows 9712** are adjacent. ^The virtual table may, if it chooses, omit extra rows 9713** that have the same value for all columns identified by "aOrderBy". 9714** ^However omitting the extra rows is optional. 9715** This mode is used for a DISTINCT query. 9716** <li value="3"><p> 9717** ^(If the sqlite3_vtab_distinct() interface returns 3, that means 9718** that the query planner needs only distinct rows but it does need the 9719** rows to be sorted.)^ ^The virtual table implementation is free to omit 9720** rows that are identical in all aOrderBy columns, if it wants to, but 9721** it is not required to omit any rows. This mode is used for queries 9722** that have both DISTINCT and ORDER BY clauses. 9723** </ol> 9724** 9725** ^For the purposes of comparing virtual table output values to see if the 9726** values are same value for sorting purposes, two NULL values are considered 9727** to be the same. In other words, the comparison operator is "IS" 9728** (or "IS NOT DISTINCT FROM") and not "==". 9729** 9730** If a virtual table implementation is unable to meet the requirements 9731** specified above, then it must not set the "orderByConsumed" flag in the 9732** [sqlite3_index_info] object or an incorrect answer may result. 9733** 9734** ^A virtual table implementation is always free to return rows in any order 9735** it wants, as long as the "orderByConsumed" flag is not set. ^When the 9736** the "orderByConsumed" flag is unset, the query planner will add extra 9737** [bytecode] to ensure that the final results returned by the SQL query are 9738** ordered correctly. The use of the "orderByConsumed" flag and the 9739** sqlite3_vtab_distinct() interface is merely an optimization. ^Careful 9740** use of the sqlite3_vtab_distinct() interface and the "orderByConsumed" 9741** flag might help queries against a virtual table to run faster. Being 9742** overly aggressive and setting the "orderByConsumed" flag when it is not 9743** valid to do so, on the other hand, might cause SQLite to return incorrect 9744** results. 9745*/ 9746SQLITE_API int sqlite3_vtab_distinct(sqlite3_index_info*); 9747 9748/* 9749** CAPI3REF: Identify and handle IN constraints in xBestIndex 9750** 9751** This interface may only be used from within an 9752** [xBestIndex|xBestIndex() method] of a [virtual table] implementation. 9753** The result of invoking this interface from any other context is 9754** undefined and probably harmful. 9755** 9756** ^(A constraint on a virtual table of the form 9757** "[IN operator|column IN (...)]" is 9758** communicated to the xBestIndex method as a 9759** [SQLITE_INDEX_CONSTRAINT_EQ] constraint.)^ If xBestIndex wants to use 9760** this constraint, it must set the corresponding 9761** aConstraintUsage[].argvIndex to a postive integer. ^(Then, under 9762** the usual mode of handling IN operators, SQLite generates [bytecode] 9763** that invokes the [xFilter|xFilter() method] once for each value 9764** on the right-hand side of the IN operator.)^ Thus the virtual table 9765** only sees a single value from the right-hand side of the IN operator 9766** at a time. 9767** 9768** In some cases, however, it would be advantageous for the virtual 9769** table to see all values on the right-hand of the IN operator all at 9770** once. The sqlite3_vtab_in() interfaces facilitates this in two ways: 9771** 9772** <ol> 9773** <li><p> 9774** ^A call to sqlite3_vtab_in(P,N,-1) will return true (non-zero) 9775** if and only if the [sqlite3_index_info|P->aConstraint][N] constraint 9776** is an [IN operator] that can be processed all at once. ^In other words, 9777** sqlite3_vtab_in() with -1 in the third argument is a mechanism 9778** by which the virtual table can ask SQLite if all-at-once processing 9779** of the IN operator is even possible. 9780** 9781** <li><p> 9782** ^A call to sqlite3_vtab_in(P,N,F) with F==1 or F==0 indicates 9783** to SQLite that the virtual table does or does not want to process 9784** the IN operator all-at-once, respectively. ^Thus when the third 9785** parameter (F) is non-negative, this interface is the mechanism by 9786** which the virtual table tells SQLite how it wants to process the 9787** IN operator. 9788** </ol> 9789** 9790** ^The sqlite3_vtab_in(P,N,F) interface can be invoked multiple times 9791** within the same xBestIndex method call. ^For any given P,N pair, 9792** the return value from sqlite3_vtab_in(P,N,F) will always be the same 9793** within the same xBestIndex call. ^If the interface returns true 9794** (non-zero), that means that the constraint is an IN operator 9795** that can be processed all-at-once. ^If the constraint is not an IN 9796** operator or cannot be processed all-at-once, then the interface returns 9797** false. 9798** 9799** ^(All-at-once processing of the IN operator is selected if both of the 9800** following conditions are met: 9801** 9802** <ol> 9803** <li><p> The P->aConstraintUsage[N].argvIndex value is set to a positive 9804** integer. This is how the virtual table tells SQLite that it wants to 9805** use the N-th constraint. 9806** 9807** <li><p> The last call to sqlite3_vtab_in(P,N,F) for which F was 9808** non-negative had F>=1. 9809** </ol>)^ 9810** 9811** ^If either or both of the conditions above are false, then SQLite uses 9812** the traditional one-at-a-time processing strategy for the IN constraint. 9813** ^If both conditions are true, then the argvIndex-th parameter to the 9814** xFilter method will be an [sqlite3_value] that appears to be NULL, 9815** but which can be passed to [sqlite3_vtab_in_first()] and 9816** [sqlite3_vtab_in_next()] to find all values on the right-hand side 9817** of the IN constraint. 9818*/ 9819SQLITE_API int sqlite3_vtab_in(sqlite3_index_info*, int iCons, int bHandle); 9820 9821/* 9822** CAPI3REF: Find all elements on the right-hand side of an IN constraint. 9823** 9824** These interfaces are only useful from within the 9825** [xFilter|xFilter() method] of a [virtual table] implementation. 9826** The result of invoking these interfaces from any other context 9827** is undefined and probably harmful. 9828** 9829** The X parameter in a call to sqlite3_vtab_in_first(X,P) or 9830** sqlite3_vtab_in_next(X,P) must be one of the parameters to the 9831** xFilter method which invokes these routines, and specifically 9832** a parameter that was previously selected for all-at-once IN constraint 9833** processing use the [sqlite3_vtab_in()] interface in the 9834** [xBestIndex|xBestIndex method]. ^(If the X parameter is not 9835** an xFilter argument that was selected for all-at-once IN constraint 9836** processing, then these routines return [SQLITE_MISUSE])^ or perhaps 9837** exhibit some other undefined or harmful behavior. 9838** 9839** ^(Use these routines to access all values on the right-hand side 9840** of the IN constraint using code like the following: 9841** 9842** <blockquote><pre> 9843** for(rc=sqlite3_vtab_in_first(pList, &pVal); 9844** rc==SQLITE_OK && pVal 9845** rc=sqlite3_vtab_in_next(pList, &pVal) 9846** ){ 9847** // do something with pVal 9848** } 9849** if( rc!=SQLITE_OK ){ 9850** // an error has occurred 9851** } 9852** </pre></blockquote>)^ 9853** 9854** ^On success, the sqlite3_vtab_in_first(X,P) and sqlite3_vtab_in_next(X,P) 9855** routines return SQLITE_OK and set *P to point to the first or next value 9856** on the RHS of the IN constraint. ^If there are no more values on the 9857** right hand side of the IN constraint, then *P is set to NULL and these 9858** routines return [SQLITE_DONE]. ^The return value might be 9859** some other value, such as SQLITE_NOMEM, in the event of a malfunction. 9860** 9861** The *ppOut values returned by these routines are only valid until the 9862** next call to either of these routines or until the end of the xFilter 9863** method from which these routines were called. If the virtual table 9864** implementation needs to retain the *ppOut values for longer, it must make 9865** copies. The *ppOut values are [protected sqlite3_value|protected]. 9866*/ 9867SQLITE_API int sqlite3_vtab_in_first(sqlite3_value *pVal, sqlite3_value **ppOut); 9868SQLITE_API int sqlite3_vtab_in_next(sqlite3_value *pVal, sqlite3_value **ppOut); 9869 9870/* 9871** CAPI3REF: Constraint values in xBestIndex() 9872** METHOD: sqlite3_index_info 9873** 9874** This API may only be used from within the [xBestIndex|xBestIndex method] 9875** of a [virtual table] implementation. The result of calling this interface 9876** from outside of an xBestIndex method are undefined and probably harmful. 9877** 9878** ^When the sqlite3_vtab_rhs_value(P,J,V) interface is invoked from within 9879** the [xBestIndex] method of a [virtual table] implementation, with P being 9880** a copy of the [sqlite3_index_info] object pointer passed into xBestIndex and 9881** J being a 0-based index into P->aConstraint[], then this routine 9882** attempts to set *V to the value of the right-hand operand of 9883** that constraint if the right-hand operand is known. ^If the 9884** right-hand operand is not known, then *V is set to a NULL pointer. 9885** ^The sqlite3_vtab_rhs_value(P,J,V) interface returns SQLITE_OK if 9886** and only if *V is set to a value. ^The sqlite3_vtab_rhs_value(P,J,V) 9887** inteface returns SQLITE_NOTFOUND if the right-hand side of the J-th 9888** constraint is not available. ^The sqlite3_vtab_rhs_value() interface 9889** can return an result code other than SQLITE_OK or SQLITE_NOTFOUND if 9890** something goes wrong. 9891** 9892** The sqlite3_vtab_rhs_value() interface is usually only successful if 9893** the right-hand operand of a constraint is a literal value in the original 9894** SQL statement. If the right-hand operand is an expression or a reference 9895** to some other column or a [host parameter], then sqlite3_vtab_rhs_value() 9896** will probably return [SQLITE_NOTFOUND]. 9897** 9898** ^(Some constraints, such as [SQLITE_INDEX_CONSTRAINT_ISNULL] and 9899** [SQLITE_INDEX_CONSTRAINT_ISNOTNULL], have no right-hand operand. For such 9900** constraints, sqlite3_vtab_rhs_value() always returns SQLITE_NOTFOUND.)^ 9901** 9902** ^The [sqlite3_value] object returned in *V is a protected sqlite3_value 9903** and remains valid for the duration of the xBestIndex method call. 9904** ^When xBestIndex returns, the sqlite3_value object returned by 9905** sqlite3_vtab_rhs_value() is automatically deallocated. 9906** 9907** The "_rhs_" in the name of this routine is an abbreviation for 9908** "Right-Hand Side". 9909*/ 9910SQLITE_API int sqlite3_vtab_rhs_value(sqlite3_index_info*, int, sqlite3_value **ppVal); 9911 9912/* 9913** CAPI3REF: Conflict resolution modes 9914** KEYWORDS: {conflict resolution mode} 9915** 9916** These constants are returned by [sqlite3_vtab_on_conflict()] to 9917** inform a [virtual table] implementation what the [ON CONFLICT] mode 9918** is for the SQL statement being evaluated. 9919** 9920** Note that the [SQLITE_IGNORE] constant is also used as a potential 9921** return value from the [sqlite3_set_authorizer()] callback and that 9922** [SQLITE_ABORT] is also a [result code]. 9923*/ 9924#define SQLITE_ROLLBACK 1 9925/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 9926#define SQLITE_FAIL 3 9927/* #define SQLITE_ABORT 4 // Also an error code */ 9928#define SQLITE_REPLACE 5 9929 9930/* 9931** CAPI3REF: Prepared Statement Scan Status Opcodes 9932** KEYWORDS: {scanstatus options} 9933** 9934** The following constants can be used for the T parameter to the 9935** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 9936** different metric for sqlite3_stmt_scanstatus() to return. 9937** 9938** When the value returned to V is a string, space to hold that string is 9939** managed by the prepared statement S and will be automatically freed when 9940** S is finalized. 9941** 9942** <dl> 9943** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 9944** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be 9945** set to the total number of times that the X-th loop has run.</dd> 9946** 9947** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 9948** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set 9949** to the total number of rows examined by all iterations of the X-th loop.</dd> 9950** 9951** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 9952** <dd>^The "double" variable pointed to by the V parameter will be set to the 9953** query planner's estimate for the average number of rows output from each 9954** iteration of the X-th loop. If the query planner's estimates was accurate, 9955** then this value will approximate the quotient NVISIT/NLOOP and the 9956** product of this value for all prior loops with the same SELECTID will 9957** be the NLOOP value for the current loop. 9958** 9959** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 9960** <dd>^The "const char *" variable pointed to by the V parameter will be set 9961** to a zero-terminated UTF-8 string containing the name of the index or table 9962** used for the X-th loop. 9963** 9964** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 9965** <dd>^The "const char *" variable pointed to by the V parameter will be set 9966** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 9967** description for the X-th loop. 9968** 9969** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 9970** <dd>^The "int" variable pointed to by the V parameter will be set to the 9971** "select-id" for the X-th loop. The select-id identifies which query or 9972** subquery the loop is part of. The main query has a select-id of zero. 9973** The select-id is the same value as is output in the first column 9974** of an [EXPLAIN QUERY PLAN] query. 9975** </dl> 9976*/ 9977#define SQLITE_SCANSTAT_NLOOP 0 9978#define SQLITE_SCANSTAT_NVISIT 1 9979#define SQLITE_SCANSTAT_EST 2 9980#define SQLITE_SCANSTAT_NAME 3 9981#define SQLITE_SCANSTAT_EXPLAIN 4 9982#define SQLITE_SCANSTAT_SELECTID 5 9983 9984/* 9985** CAPI3REF: Prepared Statement Scan Status 9986** METHOD: sqlite3_stmt 9987** 9988** This interface returns information about the predicted and measured 9989** performance for pStmt. Advanced applications can use this 9990** interface to compare the predicted and the measured performance and 9991** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 9992** 9993** Since this interface is expected to be rarely used, it is only 9994** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 9995** compile-time option. 9996** 9997** The "iScanStatusOp" parameter determines which status information to return. 9998** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 9999** of this interface is undefined. 10000** ^The requested measurement is written into a variable pointed to by 10001** the "pOut" parameter. 10002** Parameter "idx" identifies the specific loop to retrieve statistics for. 10003** Loops are numbered starting from zero. ^If idx is out of range - less than 10004** zero or greater than or equal to the total number of loops used to implement 10005** the statement - a non-zero value is returned and the variable that pOut 10006** points to is unchanged. 10007** 10008** ^Statistics might not be available for all loops in all statements. ^In cases 10009** where there exist loops with no available statistics, this function behaves 10010** as if the loop did not exist - it returns non-zero and leave the variable 10011** that pOut points to unchanged. 10012** 10013** See also: [sqlite3_stmt_scanstatus_reset()] 10014*/ 10015SQLITE_API int sqlite3_stmt_scanstatus( 10016 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 10017 int idx, /* Index of loop to report on */ 10018 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 10019 void *pOut /* Result written here */ 10020); 10021 10022/* 10023** CAPI3REF: Zero Scan-Status Counters 10024** METHOD: sqlite3_stmt 10025** 10026** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 10027** 10028** This API is only available if the library is built with pre-processor 10029** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 10030*/ 10031SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 10032 10033/* 10034** CAPI3REF: Flush caches to disk mid-transaction 10035** METHOD: sqlite3 10036** 10037** ^If a write-transaction is open on [database connection] D when the 10038** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 10039** pages in the pager-cache that are not currently in use are written out 10040** to disk. A dirty page may be in use if a database cursor created by an 10041** active SQL statement is reading from it, or if it is page 1 of a database 10042** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 10043** interface flushes caches for all schemas - "main", "temp", and 10044** any [attached] databases. 10045** 10046** ^If this function needs to obtain extra database locks before dirty pages 10047** can be flushed to disk, it does so. ^If those locks cannot be obtained 10048** immediately and there is a busy-handler callback configured, it is invoked 10049** in the usual manner. ^If the required lock still cannot be obtained, then 10050** the database is skipped and an attempt made to flush any dirty pages 10051** belonging to the next (if any) database. ^If any databases are skipped 10052** because locks cannot be obtained, but no other error occurs, this 10053** function returns SQLITE_BUSY. 10054** 10055** ^If any other error occurs while flushing dirty pages to disk (for 10056** example an IO error or out-of-memory condition), then processing is 10057** abandoned and an SQLite [error code] is returned to the caller immediately. 10058** 10059** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 10060** 10061** ^This function does not set the database handle error code or message 10062** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 10063*/ 10064SQLITE_API int sqlite3_db_cacheflush(sqlite3*); 10065 10066/* 10067** CAPI3REF: The pre-update hook. 10068** METHOD: sqlite3 10069** 10070** ^These interfaces are only available if SQLite is compiled using the 10071** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 10072** 10073** ^The [sqlite3_preupdate_hook()] interface registers a callback function 10074** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 10075** on a database table. 10076** ^At most one preupdate hook may be registered at a time on a single 10077** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 10078** the previous setting. 10079** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 10080** with a NULL pointer as the second parameter. 10081** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 10082** the first parameter to callbacks. 10083** 10084** ^The preupdate hook only fires for changes to real database tables; the 10085** preupdate hook is not invoked for changes to [virtual tables] or to 10086** system tables like sqlite_sequence or sqlite_stat1. 10087** 10088** ^The second parameter to the preupdate callback is a pointer to 10089** the [database connection] that registered the preupdate hook. 10090** ^The third parameter to the preupdate callback is one of the constants 10091** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 10092** kind of update operation that is about to occur. 10093** ^(The fourth parameter to the preupdate callback is the name of the 10094** database within the database connection that is being modified. This 10095** will be "main" for the main database or "temp" for TEMP tables or 10096** the name given after the AS keyword in the [ATTACH] statement for attached 10097** databases.)^ 10098** ^The fifth parameter to the preupdate callback is the name of the 10099** table that is being modified. 10100** 10101** For an UPDATE or DELETE operation on a [rowid table], the sixth 10102** parameter passed to the preupdate callback is the initial [rowid] of the 10103** row being modified or deleted. For an INSERT operation on a rowid table, 10104** or any operation on a WITHOUT ROWID table, the value of the sixth 10105** parameter is undefined. For an INSERT or UPDATE on a rowid table the 10106** seventh parameter is the final rowid value of the row being inserted 10107** or updated. The value of the seventh parameter passed to the callback 10108** function is not defined for operations on WITHOUT ROWID tables, or for 10109** DELETE operations on rowid tables. 10110** 10111** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 10112** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 10113** provide additional information about a preupdate event. These routines 10114** may only be called from within a preupdate callback. Invoking any of 10115** these routines from outside of a preupdate callback or with a 10116** [database connection] pointer that is different from the one supplied 10117** to the preupdate callback results in undefined and probably undesirable 10118** behavior. 10119** 10120** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 10121** in the row that is being inserted, updated, or deleted. 10122** 10123** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 10124** a [protected sqlite3_value] that contains the value of the Nth column of 10125** the table row before it is updated. The N parameter must be between 0 10126** and one less than the number of columns or the behavior will be 10127** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 10128** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 10129** behavior is undefined. The [sqlite3_value] that P points to 10130** will be destroyed when the preupdate callback returns. 10131** 10132** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 10133** a [protected sqlite3_value] that contains the value of the Nth column of 10134** the table row after it is updated. The N parameter must be between 0 10135** and one less than the number of columns or the behavior will be 10136** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 10137** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 10138** behavior is undefined. The [sqlite3_value] that P points to 10139** will be destroyed when the preupdate callback returns. 10140** 10141** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 10142** callback was invoked as a result of a direct insert, update, or delete 10143** operation; or 1 for inserts, updates, or deletes invoked by top-level 10144** triggers; or 2 for changes resulting from triggers called by top-level 10145** triggers; and so forth. 10146** 10147** When the [sqlite3_blob_write()] API is used to update a blob column, 10148** the pre-update hook is invoked with SQLITE_DELETE. This is because the 10149** in this case the new values are not available. In this case, when a 10150** callback made with op==SQLITE_DELETE is actuall a write using the 10151** sqlite3_blob_write() API, the [sqlite3_preupdate_blobwrite()] returns 10152** the index of the column being written. In other cases, where the 10153** pre-update hook is being invoked for some other reason, including a 10154** regular DELETE, sqlite3_preupdate_blobwrite() returns -1. 10155** 10156** See also: [sqlite3_update_hook()] 10157*/ 10158#if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 10159SQLITE_API void *sqlite3_preupdate_hook( 10160 sqlite3 *db, 10161 void(*xPreUpdate)( 10162 void *pCtx, /* Copy of third arg to preupdate_hook() */ 10163 sqlite3 *db, /* Database handle */ 10164 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 10165 char const *zDb, /* Database name */ 10166 char const *zName, /* Table name */ 10167 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 10168 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 10169 ), 10170 void* 10171); 10172SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 10173SQLITE_API int sqlite3_preupdate_count(sqlite3 *); 10174SQLITE_API int sqlite3_preupdate_depth(sqlite3 *); 10175SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 10176SQLITE_API int sqlite3_preupdate_blobwrite(sqlite3 *); 10177#endif 10178 10179/* 10180** CAPI3REF: Low-level system error code 10181** METHOD: sqlite3 10182** 10183** ^Attempt to return the underlying operating system error code or error 10184** number that caused the most recent I/O error or failure to open a file. 10185** The return value is OS-dependent. For example, on unix systems, after 10186** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 10187** called to get back the underlying "errno" that caused the problem, such 10188** as ENOSPC, EAUTH, EISDIR, and so forth. 10189*/ 10190SQLITE_API int sqlite3_system_errno(sqlite3*); 10191 10192/* 10193** CAPI3REF: Database Snapshot 10194** KEYWORDS: {snapshot} {sqlite3_snapshot} 10195** 10196** An instance of the snapshot object records the state of a [WAL mode] 10197** database for some specific point in history. 10198** 10199** In [WAL mode], multiple [database connections] that are open on the 10200** same database file can each be reading a different historical version 10201** of the database file. When a [database connection] begins a read 10202** transaction, that connection sees an unchanging copy of the database 10203** as it existed for the point in time when the transaction first started. 10204** Subsequent changes to the database from other connections are not seen 10205** by the reader until a new read transaction is started. 10206** 10207** The sqlite3_snapshot object records state information about an historical 10208** version of the database file so that it is possible to later open a new read 10209** transaction that sees that historical version of the database rather than 10210** the most recent version. 10211*/ 10212typedef struct sqlite3_snapshot { 10213 unsigned char hidden[48]; 10214} sqlite3_snapshot; 10215 10216/* 10217** CAPI3REF: Record A Database Snapshot 10218** CONSTRUCTOR: sqlite3_snapshot 10219** 10220** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 10221** new [sqlite3_snapshot] object that records the current state of 10222** schema S in database connection D. ^On success, the 10223** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 10224** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 10225** If there is not already a read-transaction open on schema S when 10226** this function is called, one is opened automatically. 10227** 10228** The following must be true for this function to succeed. If any of 10229** the following statements are false when sqlite3_snapshot_get() is 10230** called, SQLITE_ERROR is returned. The final value of *P is undefined 10231** in this case. 10232** 10233** <ul> 10234** <li> The database handle must not be in [autocommit mode]. 10235** 10236** <li> Schema S of [database connection] D must be a [WAL mode] database. 10237** 10238** <li> There must not be a write transaction open on schema S of database 10239** connection D. 10240** 10241** <li> One or more transactions must have been written to the current wal 10242** file since it was created on disk (by any connection). This means 10243** that a snapshot cannot be taken on a wal mode database with no wal 10244** file immediately after it is first opened. At least one transaction 10245** must be written to it first. 10246** </ul> 10247** 10248** This function may also return SQLITE_NOMEM. If it is called with the 10249** database handle in autocommit mode but fails for some other reason, 10250** whether or not a read transaction is opened on schema S is undefined. 10251** 10252** The [sqlite3_snapshot] object returned from a successful call to 10253** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 10254** to avoid a memory leak. 10255** 10256** The [sqlite3_snapshot_get()] interface is only available when the 10257** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 10258*/ 10259SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 10260 sqlite3 *db, 10261 const char *zSchema, 10262 sqlite3_snapshot **ppSnapshot 10263); 10264 10265/* 10266** CAPI3REF: Start a read transaction on an historical snapshot 10267** METHOD: sqlite3_snapshot 10268** 10269** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read 10270** transaction or upgrades an existing one for schema S of 10271** [database connection] D such that the read transaction refers to 10272** historical [snapshot] P, rather than the most recent change to the 10273** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK 10274** on success or an appropriate [error code] if it fails. 10275** 10276** ^In order to succeed, the database connection must not be in 10277** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there 10278** is already a read transaction open on schema S, then the database handle 10279** must have no active statements (SELECT statements that have been passed 10280** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()). 10281** SQLITE_ERROR is returned if either of these conditions is violated, or 10282** if schema S does not exist, or if the snapshot object is invalid. 10283** 10284** ^A call to sqlite3_snapshot_open() will fail to open if the specified 10285** snapshot has been overwritten by a [checkpoint]. In this case 10286** SQLITE_ERROR_SNAPSHOT is returned. 10287** 10288** If there is already a read transaction open when this function is 10289** invoked, then the same read transaction remains open (on the same 10290** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT 10291** is returned. If another error code - for example SQLITE_PROTOCOL or an 10292** SQLITE_IOERR error code - is returned, then the final state of the 10293** read transaction is undefined. If SQLITE_OK is returned, then the 10294** read transaction is now open on database snapshot P. 10295** 10296** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 10297** database connection D does not know that the database file for 10298** schema S is in [WAL mode]. A database connection might not know 10299** that the database file is in [WAL mode] if there has been no prior 10300** I/O on that database connection, or if the database entered [WAL mode] 10301** after the most recent I/O on the database connection.)^ 10302** (Hint: Run "[PRAGMA application_id]" against a newly opened 10303** database connection in order to make it ready to use snapshots.) 10304** 10305** The [sqlite3_snapshot_open()] interface is only available when the 10306** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 10307*/ 10308SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 10309 sqlite3 *db, 10310 const char *zSchema, 10311 sqlite3_snapshot *pSnapshot 10312); 10313 10314/* 10315** CAPI3REF: Destroy a snapshot 10316** DESTRUCTOR: sqlite3_snapshot 10317** 10318** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 10319** The application must eventually free every [sqlite3_snapshot] object 10320** using this routine to avoid a memory leak. 10321** 10322** The [sqlite3_snapshot_free()] interface is only available when the 10323** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 10324*/ 10325SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 10326 10327/* 10328** CAPI3REF: Compare the ages of two snapshot handles. 10329** METHOD: sqlite3_snapshot 10330** 10331** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 10332** of two valid snapshot handles. 10333** 10334** If the two snapshot handles are not associated with the same database 10335** file, the result of the comparison is undefined. 10336** 10337** Additionally, the result of the comparison is only valid if both of the 10338** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 10339** last time the wal file was deleted. The wal file is deleted when the 10340** database is changed back to rollback mode or when the number of database 10341** clients drops to zero. If either snapshot handle was obtained before the 10342** wal file was last deleted, the value returned by this function 10343** is undefined. 10344** 10345** Otherwise, this API returns a negative value if P1 refers to an older 10346** snapshot than P2, zero if the two handles refer to the same database 10347** snapshot, and a positive value if P1 is a newer snapshot than P2. 10348** 10349** This interface is only available if SQLite is compiled with the 10350** [SQLITE_ENABLE_SNAPSHOT] option. 10351*/ 10352SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 10353 sqlite3_snapshot *p1, 10354 sqlite3_snapshot *p2 10355); 10356 10357/* 10358** CAPI3REF: Recover snapshots from a wal file 10359** METHOD: sqlite3_snapshot 10360** 10361** If a [WAL file] remains on disk after all database connections close 10362** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control] 10363** or because the last process to have the database opened exited without 10364** calling [sqlite3_close()]) and a new connection is subsequently opened 10365** on that database and [WAL file], the [sqlite3_snapshot_open()] interface 10366** will only be able to open the last transaction added to the WAL file 10367** even though the WAL file contains other valid transactions. 10368** 10369** This function attempts to scan the WAL file associated with database zDb 10370** of database handle db and make all valid snapshots available to 10371** sqlite3_snapshot_open(). It is an error if there is already a read 10372** transaction open on the database, or if the database is not a WAL mode 10373** database. 10374** 10375** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 10376** 10377** This interface is only available if SQLite is compiled with the 10378** [SQLITE_ENABLE_SNAPSHOT] option. 10379*/ 10380SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 10381 10382/* 10383** CAPI3REF: Serialize a database 10384** 10385** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory 10386** that is a serialization of the S database on [database connection] D. 10387** If P is not a NULL pointer, then the size of the database in bytes 10388** is written into *P. 10389** 10390** For an ordinary on-disk database file, the serialization is just a 10391** copy of the disk file. For an in-memory database or a "TEMP" database, 10392** the serialization is the same sequence of bytes which would be written 10393** to disk if that database where backed up to disk. 10394** 10395** The usual case is that sqlite3_serialize() copies the serialization of 10396** the database into memory obtained from [sqlite3_malloc64()] and returns 10397** a pointer to that memory. The caller is responsible for freeing the 10398** returned value to avoid a memory leak. However, if the F argument 10399** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations 10400** are made, and the sqlite3_serialize() function will return a pointer 10401** to the contiguous memory representation of the database that SQLite 10402** is currently using for that database, or NULL if the no such contiguous 10403** memory representation of the database exists. A contiguous memory 10404** representation of the database will usually only exist if there has 10405** been a prior call to [sqlite3_deserialize(D,S,...)] with the same 10406** values of D and S. 10407** The size of the database is written into *P even if the 10408** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy 10409** of the database exists. 10410** 10411** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the 10412** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory 10413** allocation error occurs. 10414** 10415** This interface is omitted if SQLite is compiled with the 10416** [SQLITE_OMIT_DESERIALIZE] option. 10417*/ 10418SQLITE_API unsigned char *sqlite3_serialize( 10419 sqlite3 *db, /* The database connection */ 10420 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */ 10421 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */ 10422 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */ 10423); 10424 10425/* 10426** CAPI3REF: Flags for sqlite3_serialize 10427** 10428** Zero or more of the following constants can be OR-ed together for 10429** the F argument to [sqlite3_serialize(D,S,P,F)]. 10430** 10431** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return 10432** a pointer to contiguous in-memory database that it is currently using, 10433** without making a copy of the database. If SQLite is not currently using 10434** a contiguous in-memory database, then this option causes 10435** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be 10436** using a contiguous in-memory database if it has been initialized by a 10437** prior call to [sqlite3_deserialize()]. 10438*/ 10439#define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */ 10440 10441/* 10442** CAPI3REF: Deserialize a database 10443** 10444** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the 10445** [database connection] D to disconnect from database S and then 10446** reopen S as an in-memory database based on the serialization contained 10447** in P. The serialized database P is N bytes in size. M is the size of 10448** the buffer P, which might be larger than N. If M is larger than N, and 10449** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is 10450** permitted to add content to the in-memory database as long as the total 10451** size does not exceed M bytes. 10452** 10453** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will 10454** invoke sqlite3_free() on the serialization buffer when the database 10455** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then 10456** SQLite will try to increase the buffer size using sqlite3_realloc64() 10457** if writes on the database cause it to grow larger than M bytes. 10458** 10459** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the 10460** database is currently in a read transaction or is involved in a backup 10461** operation. 10462** 10463** It is not possible to deserialized into the TEMP database. If the 10464** S argument to sqlite3_deserialize(D,S,P,N,M,F) is "temp" then the 10465** function returns SQLITE_ERROR. 10466** 10467** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the 10468** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then 10469** [sqlite3_free()] is invoked on argument P prior to returning. 10470** 10471** This interface is omitted if SQLite is compiled with the 10472** [SQLITE_OMIT_DESERIALIZE] option. 10473*/ 10474SQLITE_API int sqlite3_deserialize( 10475 sqlite3 *db, /* The database connection */ 10476 const char *zSchema, /* Which DB to reopen with the deserialization */ 10477 unsigned char *pData, /* The serialized database content */ 10478 sqlite3_int64 szDb, /* Number bytes in the deserialization */ 10479 sqlite3_int64 szBuf, /* Total size of buffer pData[] */ 10480 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */ 10481); 10482 10483/* 10484** CAPI3REF: Flags for sqlite3_deserialize() 10485** 10486** The following are allowed values for 6th argument (the F argument) to 10487** the [sqlite3_deserialize(D,S,P,N,M,F)] interface. 10488** 10489** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization 10490** in the P argument is held in memory obtained from [sqlite3_malloc64()] 10491** and that SQLite should take ownership of this memory and automatically 10492** free it when it has finished using it. Without this flag, the caller 10493** is responsible for freeing any dynamically allocated memory. 10494** 10495** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to 10496** grow the size of the database using calls to [sqlite3_realloc64()]. This 10497** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used. 10498** Without this flag, the deserialized database cannot increase in size beyond 10499** the number of bytes specified by the M parameter. 10500** 10501** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database 10502** should be treated as read-only. 10503*/ 10504#define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */ 10505#define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */ 10506#define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */ 10507 10508/* 10509** Undo the hack that converts floating point types to integer for 10510** builds on processors without floating point support. 10511*/ 10512#ifdef SQLITE_OMIT_FLOATING_POINT 10513# undef double 10514#endif 10515 10516#ifdef __cplusplus 10517} /* End of the 'extern "C"' block */ 10518#endif 10519#endif /* SQLITE3_H */ 10520 10521/******** Begin file sqlite3rtree.h *********/ 10522/* 10523** 2010 August 30 10524** 10525** The author disclaims copyright to this source code. In place of 10526** a legal notice, here is a blessing: 10527** 10528** May you do good and not evil. 10529** May you find forgiveness for yourself and forgive others. 10530** May you share freely, never taking more than you give. 10531** 10532************************************************************************* 10533*/ 10534 10535#ifndef _SQLITE3RTREE_H_ 10536#define _SQLITE3RTREE_H_ 10537 10538 10539#ifdef __cplusplus 10540extern "C" { 10541#endif 10542 10543typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 10544typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 10545 10546/* The double-precision datatype used by RTree depends on the 10547** SQLITE_RTREE_INT_ONLY compile-time option. 10548*/ 10549#ifdef SQLITE_RTREE_INT_ONLY 10550 typedef sqlite3_int64 sqlite3_rtree_dbl; 10551#else 10552 typedef double sqlite3_rtree_dbl; 10553#endif 10554 10555/* 10556** Register a geometry callback named zGeom that can be used as part of an 10557** R-Tree geometry query as follows: 10558** 10559** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 10560*/ 10561SQLITE_API int sqlite3_rtree_geometry_callback( 10562 sqlite3 *db, 10563 const char *zGeom, 10564 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 10565 void *pContext 10566); 10567 10568 10569/* 10570** A pointer to a structure of the following type is passed as the first 10571** argument to callbacks registered using rtree_geometry_callback(). 10572*/ 10573struct sqlite3_rtree_geometry { 10574 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 10575 int nParam; /* Size of array aParam[] */ 10576 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 10577 void *pUser; /* Callback implementation user data */ 10578 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 10579}; 10580 10581/* 10582** Register a 2nd-generation geometry callback named zScore that can be 10583** used as part of an R-Tree geometry query as follows: 10584** 10585** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 10586*/ 10587SQLITE_API int sqlite3_rtree_query_callback( 10588 sqlite3 *db, 10589 const char *zQueryFunc, 10590 int (*xQueryFunc)(sqlite3_rtree_query_info*), 10591 void *pContext, 10592 void (*xDestructor)(void*) 10593); 10594 10595 10596/* 10597** A pointer to a structure of the following type is passed as the 10598** argument to scored geometry callback registered using 10599** sqlite3_rtree_query_callback(). 10600** 10601** Note that the first 5 fields of this structure are identical to 10602** sqlite3_rtree_geometry. This structure is a subclass of 10603** sqlite3_rtree_geometry. 10604*/ 10605struct sqlite3_rtree_query_info { 10606 void *pContext; /* pContext from when function registered */ 10607 int nParam; /* Number of function parameters */ 10608 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 10609 void *pUser; /* callback can use this, if desired */ 10610 void (*xDelUser)(void*); /* function to free pUser */ 10611 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 10612 unsigned int *anQueue; /* Number of pending entries in the queue */ 10613 int nCoord; /* Number of coordinates */ 10614 int iLevel; /* Level of current node or entry */ 10615 int mxLevel; /* The largest iLevel value in the tree */ 10616 sqlite3_int64 iRowid; /* Rowid for current entry */ 10617 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 10618 int eParentWithin; /* Visibility of parent node */ 10619 int eWithin; /* OUT: Visibility */ 10620 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 10621 /* The following fields are only available in 3.8.11 and later */ 10622 sqlite3_value **apSqlParam; /* Original SQL values of parameters */ 10623}; 10624 10625/* 10626** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 10627*/ 10628#define NOT_WITHIN 0 /* Object completely outside of query region */ 10629#define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 10630#define FULLY_WITHIN 2 /* Object fully contained within query region */ 10631 10632 10633#ifdef __cplusplus 10634} /* end of the 'extern "C"' block */ 10635#endif 10636 10637#endif /* ifndef _SQLITE3RTREE_H_ */ 10638 10639/******** End of sqlite3rtree.h *********/ 10640/******** Begin file sqlite3session.h *********/ 10641 10642#if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) 10643#define __SQLITESESSION_H_ 1 10644 10645/* 10646** Make sure we can call this stuff from C++. 10647*/ 10648#ifdef __cplusplus 10649extern "C" { 10650#endif 10651 10652 10653/* 10654** CAPI3REF: Session Object Handle 10655** 10656** An instance of this object is a [session] that can be used to 10657** record changes to a database. 10658*/ 10659typedef struct sqlite3_session sqlite3_session; 10660 10661/* 10662** CAPI3REF: Changeset Iterator Handle 10663** 10664** An instance of this object acts as a cursor for iterating 10665** over the elements of a [changeset] or [patchset]. 10666*/ 10667typedef struct sqlite3_changeset_iter sqlite3_changeset_iter; 10668 10669/* 10670** CAPI3REF: Create A New Session Object 10671** CONSTRUCTOR: sqlite3_session 10672** 10673** Create a new session object attached to database handle db. If successful, 10674** a pointer to the new object is written to *ppSession and SQLITE_OK is 10675** returned. If an error occurs, *ppSession is set to NULL and an SQLite 10676** error code (e.g. SQLITE_NOMEM) is returned. 10677** 10678** It is possible to create multiple session objects attached to a single 10679** database handle. 10680** 10681** Session objects created using this function should be deleted using the 10682** [sqlite3session_delete()] function before the database handle that they 10683** are attached to is itself closed. If the database handle is closed before 10684** the session object is deleted, then the results of calling any session 10685** module function, including [sqlite3session_delete()] on the session object 10686** are undefined. 10687** 10688** Because the session module uses the [sqlite3_preupdate_hook()] API, it 10689** is not possible for an application to register a pre-update hook on a 10690** database handle that has one or more session objects attached. Nor is 10691** it possible to create a session object attached to a database handle for 10692** which a pre-update hook is already defined. The results of attempting 10693** either of these things are undefined. 10694** 10695** The session object will be used to create changesets for tables in 10696** database zDb, where zDb is either "main", or "temp", or the name of an 10697** attached database. It is not an error if database zDb is not attached 10698** to the database when the session object is created. 10699*/ 10700SQLITE_API int sqlite3session_create( 10701 sqlite3 *db, /* Database handle */ 10702 const char *zDb, /* Name of db (e.g. "main") */ 10703 sqlite3_session **ppSession /* OUT: New session object */ 10704); 10705 10706/* 10707** CAPI3REF: Delete A Session Object 10708** DESTRUCTOR: sqlite3_session 10709** 10710** Delete a session object previously allocated using 10711** [sqlite3session_create()]. Once a session object has been deleted, the 10712** results of attempting to use pSession with any other session module 10713** function are undefined. 10714** 10715** Session objects must be deleted before the database handle to which they 10716** are attached is closed. Refer to the documentation for 10717** [sqlite3session_create()] for details. 10718*/ 10719SQLITE_API void sqlite3session_delete(sqlite3_session *pSession); 10720 10721/* 10722** CAPIREF: Conigure a Session Object 10723** METHOD: sqlite3_session 10724** 10725** This method is used to configure a session object after it has been 10726** created. At present the only valid value for the second parameter is 10727** [SQLITE_SESSION_OBJCONFIG_SIZE]. 10728** 10729** Arguments for sqlite3session_object_config() 10730** 10731** The following values may passed as the the 4th parameter to 10732** sqlite3session_object_config(). 10733** 10734** <dt>SQLITE_SESSION_OBJCONFIG_SIZE <dd> 10735** This option is used to set, clear or query the flag that enables 10736** the [sqlite3session_changeset_size()] API. Because it imposes some 10737** computational overhead, this API is disabled by default. Argument 10738** pArg must point to a value of type (int). If the value is initially 10739** 0, then the sqlite3session_changeset_size() API is disabled. If it 10740** is greater than 0, then the same API is enabled. Or, if the initial 10741** value is less than zero, no change is made. In all cases the (int) 10742** variable is set to 1 if the sqlite3session_changeset_size() API is 10743** enabled following the current call, or 0 otherwise. 10744** 10745** It is an error (SQLITE_MISUSE) to attempt to modify this setting after 10746** the first table has been attached to the session object. 10747*/ 10748SQLITE_API int sqlite3session_object_config(sqlite3_session*, int op, void *pArg); 10749 10750/* 10751*/ 10752#define SQLITE_SESSION_OBJCONFIG_SIZE 1 10753 10754/* 10755** CAPI3REF: Enable Or Disable A Session Object 10756** METHOD: sqlite3_session 10757** 10758** Enable or disable the recording of changes by a session object. When 10759** enabled, a session object records changes made to the database. When 10760** disabled - it does not. A newly created session object is enabled. 10761** Refer to the documentation for [sqlite3session_changeset()] for further 10762** details regarding how enabling and disabling a session object affects 10763** the eventual changesets. 10764** 10765** Passing zero to this function disables the session. Passing a value 10766** greater than zero enables it. Passing a value less than zero is a 10767** no-op, and may be used to query the current state of the session. 10768** 10769** The return value indicates the final state of the session object: 0 if 10770** the session is disabled, or 1 if it is enabled. 10771*/ 10772SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable); 10773 10774/* 10775** CAPI3REF: Set Or Clear the Indirect Change Flag 10776** METHOD: sqlite3_session 10777** 10778** Each change recorded by a session object is marked as either direct or 10779** indirect. A change is marked as indirect if either: 10780** 10781** <ul> 10782** <li> The session object "indirect" flag is set when the change is 10783** made, or 10784** <li> The change is made by an SQL trigger or foreign key action 10785** instead of directly as a result of a users SQL statement. 10786** </ul> 10787** 10788** If a single row is affected by more than one operation within a session, 10789** then the change is considered indirect if all operations meet the criteria 10790** for an indirect change above, or direct otherwise. 10791** 10792** This function is used to set, clear or query the session object indirect 10793** flag. If the second argument passed to this function is zero, then the 10794** indirect flag is cleared. If it is greater than zero, the indirect flag 10795** is set. Passing a value less than zero does not modify the current value 10796** of the indirect flag, and may be used to query the current state of the 10797** indirect flag for the specified session object. 10798** 10799** The return value indicates the final state of the indirect flag: 0 if 10800** it is clear, or 1 if it is set. 10801*/ 10802SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect); 10803 10804/* 10805** CAPI3REF: Attach A Table To A Session Object 10806** METHOD: sqlite3_session 10807** 10808** If argument zTab is not NULL, then it is the name of a table to attach 10809** to the session object passed as the first argument. All subsequent changes 10810** made to the table while the session object is enabled will be recorded. See 10811** documentation for [sqlite3session_changeset()] for further details. 10812** 10813** Or, if argument zTab is NULL, then changes are recorded for all tables 10814** in the database. If additional tables are added to the database (by 10815** executing "CREATE TABLE" statements) after this call is made, changes for 10816** the new tables are also recorded. 10817** 10818** Changes can only be recorded for tables that have a PRIMARY KEY explicitly 10819** defined as part of their CREATE TABLE statement. It does not matter if the 10820** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY 10821** KEY may consist of a single column, or may be a composite key. 10822** 10823** It is not an error if the named table does not exist in the database. Nor 10824** is it an error if the named table does not have a PRIMARY KEY. However, 10825** no changes will be recorded in either of these scenarios. 10826** 10827** Changes are not recorded for individual rows that have NULL values stored 10828** in one or more of their PRIMARY KEY columns. 10829** 10830** SQLITE_OK is returned if the call completes without error. Or, if an error 10831** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned. 10832** 10833** <h3>Special sqlite_stat1 Handling</h3> 10834** 10835** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to 10836** some of the rules above. In SQLite, the schema of sqlite_stat1 is: 10837** <pre> 10838** CREATE TABLE sqlite_stat1(tbl,idx,stat) 10839** </pre> 10840** 10841** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are 10842** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes 10843** are recorded for rows for which (idx IS NULL) is true. However, for such 10844** rows a zero-length blob (SQL value X'') is stored in the changeset or 10845** patchset instead of a NULL value. This allows such changesets to be 10846** manipulated by legacy implementations of sqlite3changeset_invert(), 10847** concat() and similar. 10848** 10849** The sqlite3changeset_apply() function automatically converts the 10850** zero-length blob back to a NULL value when updating the sqlite_stat1 10851** table. However, if the application calls sqlite3changeset_new(), 10852** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset 10853** iterator directly (including on a changeset iterator passed to a 10854** conflict-handler callback) then the X'' value is returned. The application 10855** must translate X'' to NULL itself if required. 10856** 10857** Legacy (older than 3.22.0) versions of the sessions module cannot capture 10858** changes made to the sqlite_stat1 table. Legacy versions of the 10859** sqlite3changeset_apply() function silently ignore any modifications to the 10860** sqlite_stat1 table that are part of a changeset or patchset. 10861*/ 10862SQLITE_API int sqlite3session_attach( 10863 sqlite3_session *pSession, /* Session object */ 10864 const char *zTab /* Table name */ 10865); 10866 10867/* 10868** CAPI3REF: Set a table filter on a Session Object. 10869** METHOD: sqlite3_session 10870** 10871** The second argument (xFilter) is the "filter callback". For changes to rows 10872** in tables that are not attached to the Session object, the filter is called 10873** to determine whether changes to the table's rows should be tracked or not. 10874** If xFilter returns 0, changes are not tracked. Note that once a table is 10875** attached, xFilter will not be called again. 10876*/ 10877SQLITE_API void sqlite3session_table_filter( 10878 sqlite3_session *pSession, /* Session object */ 10879 int(*xFilter)( 10880 void *pCtx, /* Copy of third arg to _filter_table() */ 10881 const char *zTab /* Table name */ 10882 ), 10883 void *pCtx /* First argument passed to xFilter */ 10884); 10885 10886/* 10887** CAPI3REF: Generate A Changeset From A Session Object 10888** METHOD: sqlite3_session 10889** 10890** Obtain a changeset containing changes to the tables attached to the 10891** session object passed as the first argument. If successful, 10892** set *ppChangeset to point to a buffer containing the changeset 10893** and *pnChangeset to the size of the changeset in bytes before returning 10894** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to 10895** zero and return an SQLite error code. 10896** 10897** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes, 10898** each representing a change to a single row of an attached table. An INSERT 10899** change contains the values of each field of a new database row. A DELETE 10900** contains the original values of each field of a deleted database row. An 10901** UPDATE change contains the original values of each field of an updated 10902** database row along with the updated values for each updated non-primary-key 10903** column. It is not possible for an UPDATE change to represent a change that 10904** modifies the values of primary key columns. If such a change is made, it 10905** is represented in a changeset as a DELETE followed by an INSERT. 10906** 10907** Changes are not recorded for rows that have NULL values stored in one or 10908** more of their PRIMARY KEY columns. If such a row is inserted or deleted, 10909** no corresponding change is present in the changesets returned by this 10910** function. If an existing row with one or more NULL values stored in 10911** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL, 10912** only an INSERT is appears in the changeset. Similarly, if an existing row 10913** with non-NULL PRIMARY KEY values is updated so that one or more of its 10914** PRIMARY KEY columns are set to NULL, the resulting changeset contains a 10915** DELETE change only. 10916** 10917** The contents of a changeset may be traversed using an iterator created 10918** using the [sqlite3changeset_start()] API. A changeset may be applied to 10919** a database with a compatible schema using the [sqlite3changeset_apply()] 10920** API. 10921** 10922** Within a changeset generated by this function, all changes related to a 10923** single table are grouped together. In other words, when iterating through 10924** a changeset or when applying a changeset to a database, all changes related 10925** to a single table are processed before moving on to the next table. Tables 10926** are sorted in the same order in which they were attached (or auto-attached) 10927** to the sqlite3_session object. The order in which the changes related to 10928** a single table are stored is undefined. 10929** 10930** Following a successful call to this function, it is the responsibility of 10931** the caller to eventually free the buffer that *ppChangeset points to using 10932** [sqlite3_free()]. 10933** 10934** <h3>Changeset Generation</h3> 10935** 10936** Once a table has been attached to a session object, the session object 10937** records the primary key values of all new rows inserted into the table. 10938** It also records the original primary key and other column values of any 10939** deleted or updated rows. For each unique primary key value, data is only 10940** recorded once - the first time a row with said primary key is inserted, 10941** updated or deleted in the lifetime of the session. 10942** 10943** There is one exception to the previous paragraph: when a row is inserted, 10944** updated or deleted, if one or more of its primary key columns contain a 10945** NULL value, no record of the change is made. 10946** 10947** The session object therefore accumulates two types of records - those 10948** that consist of primary key values only (created when the user inserts 10949** a new record) and those that consist of the primary key values and the 10950** original values of other table columns (created when the users deletes 10951** or updates a record). 10952** 10953** When this function is called, the requested changeset is created using 10954** both the accumulated records and the current contents of the database 10955** file. Specifically: 10956** 10957** <ul> 10958** <li> For each record generated by an insert, the database is queried 10959** for a row with a matching primary key. If one is found, an INSERT 10960** change is added to the changeset. If no such row is found, no change 10961** is added to the changeset. 10962** 10963** <li> For each record generated by an update or delete, the database is 10964** queried for a row with a matching primary key. If such a row is 10965** found and one or more of the non-primary key fields have been 10966** modified from their original values, an UPDATE change is added to 10967** the changeset. Or, if no such row is found in the table, a DELETE 10968** change is added to the changeset. If there is a row with a matching 10969** primary key in the database, but all fields contain their original 10970** values, no change is added to the changeset. 10971** </ul> 10972** 10973** This means, amongst other things, that if a row is inserted and then later 10974** deleted while a session object is active, neither the insert nor the delete 10975** will be present in the changeset. Or if a row is deleted and then later a 10976** row with the same primary key values inserted while a session object is 10977** active, the resulting changeset will contain an UPDATE change instead of 10978** a DELETE and an INSERT. 10979** 10980** When a session object is disabled (see the [sqlite3session_enable()] API), 10981** it does not accumulate records when rows are inserted, updated or deleted. 10982** This may appear to have some counter-intuitive effects if a single row 10983** is written to more than once during a session. For example, if a row 10984** is inserted while a session object is enabled, then later deleted while 10985** the same session object is disabled, no INSERT record will appear in the 10986** changeset, even though the delete took place while the session was disabled. 10987** Or, if one field of a row is updated while a session is disabled, and 10988** another field of the same row is updated while the session is enabled, the 10989** resulting changeset will contain an UPDATE change that updates both fields. 10990*/ 10991SQLITE_API int sqlite3session_changeset( 10992 sqlite3_session *pSession, /* Session object */ 10993 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */ 10994 void **ppChangeset /* OUT: Buffer containing changeset */ 10995); 10996 10997/* 10998** CAPI3REF: Return An Upper-limit For The Size Of The Changeset 10999** METHOD: sqlite3_session 11000** 11001** By default, this function always returns 0. For it to return 11002** a useful result, the sqlite3_session object must have been configured 11003** to enable this API using sqlite3session_object_config() with the 11004** SQLITE_SESSION_OBJCONFIG_SIZE verb. 11005** 11006** When enabled, this function returns an upper limit, in bytes, for the size 11007** of the changeset that might be produced if sqlite3session_changeset() were 11008** called. The final changeset size might be equal to or smaller than the 11009** size in bytes returned by this function. 11010*/ 11011SQLITE_API sqlite3_int64 sqlite3session_changeset_size(sqlite3_session *pSession); 11012 11013/* 11014** CAPI3REF: Load The Difference Between Tables Into A Session 11015** METHOD: sqlite3_session 11016** 11017** If it is not already attached to the session object passed as the first 11018** argument, this function attaches table zTbl in the same manner as the 11019** [sqlite3session_attach()] function. If zTbl does not exist, or if it 11020** does not have a primary key, this function is a no-op (but does not return 11021** an error). 11022** 11023** Argument zFromDb must be the name of a database ("main", "temp" etc.) 11024** attached to the same database handle as the session object that contains 11025** a table compatible with the table attached to the session by this function. 11026** A table is considered compatible if it: 11027** 11028** <ul> 11029** <li> Has the same name, 11030** <li> Has the same set of columns declared in the same order, and 11031** <li> Has the same PRIMARY KEY definition. 11032** </ul> 11033** 11034** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables 11035** are compatible but do not have any PRIMARY KEY columns, it is not an error 11036** but no changes are added to the session object. As with other session 11037** APIs, tables without PRIMARY KEYs are simply ignored. 11038** 11039** This function adds a set of changes to the session object that could be 11040** used to update the table in database zFrom (call this the "from-table") 11041** so that its content is the same as the table attached to the session 11042** object (call this the "to-table"). Specifically: 11043** 11044** <ul> 11045** <li> For each row (primary key) that exists in the to-table but not in 11046** the from-table, an INSERT record is added to the session object. 11047** 11048** <li> For each row (primary key) that exists in the to-table but not in 11049** the from-table, a DELETE record is added to the session object. 11050** 11051** <li> For each row (primary key) that exists in both tables, but features 11052** different non-PK values in each, an UPDATE record is added to the 11053** session. 11054** </ul> 11055** 11056** To clarify, if this function is called and then a changeset constructed 11057** using [sqlite3session_changeset()], then after applying that changeset to 11058** database zFrom the contents of the two compatible tables would be 11059** identical. 11060** 11061** It an error if database zFrom does not exist or does not contain the 11062** required compatible table. 11063** 11064** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite 11065** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg 11066** may be set to point to a buffer containing an English language error 11067** message. It is the responsibility of the caller to free this buffer using 11068** sqlite3_free(). 11069*/ 11070SQLITE_API int sqlite3session_diff( 11071 sqlite3_session *pSession, 11072 const char *zFromDb, 11073 const char *zTbl, 11074 char **pzErrMsg 11075); 11076 11077 11078/* 11079** CAPI3REF: Generate A Patchset From A Session Object 11080** METHOD: sqlite3_session 11081** 11082** The differences between a patchset and a changeset are that: 11083** 11084** <ul> 11085** <li> DELETE records consist of the primary key fields only. The 11086** original values of other fields are omitted. 11087** <li> The original values of any modified fields are omitted from 11088** UPDATE records. 11089** </ul> 11090** 11091** A patchset blob may be used with up to date versions of all 11092** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(), 11093** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly, 11094** attempting to use a patchset blob with old versions of the 11095** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error. 11096** 11097** Because the non-primary key "old.*" fields are omitted, no 11098** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset 11099** is passed to the sqlite3changeset_apply() API. Other conflict types work 11100** in the same way as for changesets. 11101** 11102** Changes within a patchset are ordered in the same way as for changesets 11103** generated by the sqlite3session_changeset() function (i.e. all changes for 11104** a single table are grouped together, tables appear in the order in which 11105** they were attached to the session object). 11106*/ 11107SQLITE_API int sqlite3session_patchset( 11108 sqlite3_session *pSession, /* Session object */ 11109 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */ 11110 void **ppPatchset /* OUT: Buffer containing patchset */ 11111); 11112 11113/* 11114** CAPI3REF: Test if a changeset has recorded any changes. 11115** 11116** Return non-zero if no changes to attached tables have been recorded by 11117** the session object passed as the first argument. Otherwise, if one or 11118** more changes have been recorded, return zero. 11119** 11120** Even if this function returns zero, it is possible that calling 11121** [sqlite3session_changeset()] on the session handle may still return a 11122** changeset that contains no changes. This can happen when a row in 11123** an attached table is modified and then later on the original values 11124** are restored. However, if this function returns non-zero, then it is 11125** guaranteed that a call to sqlite3session_changeset() will return a 11126** changeset containing zero changes. 11127*/ 11128SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession); 11129 11130/* 11131** CAPI3REF: Query for the amount of heap memory used by a session object. 11132** 11133** This API returns the total amount of heap memory in bytes currently 11134** used by the session object passed as the only argument. 11135*/ 11136SQLITE_API sqlite3_int64 sqlite3session_memory_used(sqlite3_session *pSession); 11137 11138/* 11139** CAPI3REF: Create An Iterator To Traverse A Changeset 11140** CONSTRUCTOR: sqlite3_changeset_iter 11141** 11142** Create an iterator used to iterate through the contents of a changeset. 11143** If successful, *pp is set to point to the iterator handle and SQLITE_OK 11144** is returned. Otherwise, if an error occurs, *pp is set to zero and an 11145** SQLite error code is returned. 11146** 11147** The following functions can be used to advance and query a changeset 11148** iterator created by this function: 11149** 11150** <ul> 11151** <li> [sqlite3changeset_next()] 11152** <li> [sqlite3changeset_op()] 11153** <li> [sqlite3changeset_new()] 11154** <li> [sqlite3changeset_old()] 11155** </ul> 11156** 11157** It is the responsibility of the caller to eventually destroy the iterator 11158** by passing it to [sqlite3changeset_finalize()]. The buffer containing the 11159** changeset (pChangeset) must remain valid until after the iterator is 11160** destroyed. 11161** 11162** Assuming the changeset blob was created by one of the 11163** [sqlite3session_changeset()], [sqlite3changeset_concat()] or 11164** [sqlite3changeset_invert()] functions, all changes within the changeset 11165** that apply to a single table are grouped together. This means that when 11166** an application iterates through a changeset using an iterator created by 11167** this function, all changes that relate to a single table are visited 11168** consecutively. There is no chance that the iterator will visit a change 11169** the applies to table X, then one for table Y, and then later on visit 11170** another change for table X. 11171** 11172** The behavior of sqlite3changeset_start_v2() and its streaming equivalent 11173** may be modified by passing a combination of 11174** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter. 11175** 11176** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b> 11177** and therefore subject to change. 11178*/ 11179SQLITE_API int sqlite3changeset_start( 11180 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 11181 int nChangeset, /* Size of changeset blob in bytes */ 11182 void *pChangeset /* Pointer to blob containing changeset */ 11183); 11184SQLITE_API int sqlite3changeset_start_v2( 11185 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */ 11186 int nChangeset, /* Size of changeset blob in bytes */ 11187 void *pChangeset, /* Pointer to blob containing changeset */ 11188 int flags /* SESSION_CHANGESETSTART_* flags */ 11189); 11190 11191/* 11192** CAPI3REF: Flags for sqlite3changeset_start_v2 11193** 11194** The following flags may passed via the 4th parameter to 11195** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]: 11196** 11197** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 11198** Invert the changeset while iterating through it. This is equivalent to 11199** inverting a changeset using sqlite3changeset_invert() before applying it. 11200** It is an error to specify this flag with a patchset. 11201*/ 11202#define SQLITE_CHANGESETSTART_INVERT 0x0002 11203 11204 11205/* 11206** CAPI3REF: Advance A Changeset Iterator 11207** METHOD: sqlite3_changeset_iter 11208** 11209** This function may only be used with iterators created by the function 11210** [sqlite3changeset_start()]. If it is called on an iterator passed to 11211** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE 11212** is returned and the call has no effect. 11213** 11214** Immediately after an iterator is created by sqlite3changeset_start(), it 11215** does not point to any change in the changeset. Assuming the changeset 11216** is not empty, the first call to this function advances the iterator to 11217** point to the first change in the changeset. Each subsequent call advances 11218** the iterator to point to the next change in the changeset (if any). If 11219** no error occurs and the iterator points to a valid change after a call 11220** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned. 11221** Otherwise, if all changes in the changeset have already been visited, 11222** SQLITE_DONE is returned. 11223** 11224** If an error occurs, an SQLite error code is returned. Possible error 11225** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or 11226** SQLITE_NOMEM. 11227*/ 11228SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter); 11229 11230/* 11231** CAPI3REF: Obtain The Current Operation From A Changeset Iterator 11232** METHOD: sqlite3_changeset_iter 11233** 11234** The pIter argument passed to this function may either be an iterator 11235** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 11236** created by [sqlite3changeset_start()]. In the latter case, the most recent 11237** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this 11238** is not the case, this function returns [SQLITE_MISUSE]. 11239** 11240** Arguments pOp, pnCol and pzTab may not be NULL. Upon return, three 11241** outputs are set through these pointers: 11242** 11243** *pOp is set to one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], 11244** depending on the type of change that the iterator currently points to; 11245** 11246** *pnCol is set to the number of columns in the table affected by the change; and 11247** 11248** *pzTab is set to point to a nul-terminated utf-8 encoded string containing 11249** the name of the table affected by the current change. The buffer remains 11250** valid until either sqlite3changeset_next() is called on the iterator 11251** or until the conflict-handler function returns. 11252** 11253** If pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change 11254** is an indirect change, or false (0) otherwise. See the documentation for 11255** [sqlite3session_indirect()] for a description of direct and indirect 11256** changes. 11257** 11258** If no error occurs, SQLITE_OK is returned. If an error does occur, an 11259** SQLite error code is returned. The values of the output variables may not 11260** be trusted in this case. 11261*/ 11262SQLITE_API int sqlite3changeset_op( 11263 sqlite3_changeset_iter *pIter, /* Iterator object */ 11264 const char **pzTab, /* OUT: Pointer to table name */ 11265 int *pnCol, /* OUT: Number of columns in table */ 11266 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */ 11267 int *pbIndirect /* OUT: True for an 'indirect' change */ 11268); 11269 11270/* 11271** CAPI3REF: Obtain The Primary Key Definition Of A Table 11272** METHOD: sqlite3_changeset_iter 11273** 11274** For each modified table, a changeset includes the following: 11275** 11276** <ul> 11277** <li> The number of columns in the table, and 11278** <li> Which of those columns make up the tables PRIMARY KEY. 11279** </ul> 11280** 11281** This function is used to find which columns comprise the PRIMARY KEY of 11282** the table modified by the change that iterator pIter currently points to. 11283** If successful, *pabPK is set to point to an array of nCol entries, where 11284** nCol is the number of columns in the table. Elements of *pabPK are set to 11285** 0x01 if the corresponding column is part of the tables primary key, or 11286** 0x00 if it is not. 11287** 11288** If argument pnCol is not NULL, then *pnCol is set to the number of columns 11289** in the table. 11290** 11291** If this function is called when the iterator does not point to a valid 11292** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise, 11293** SQLITE_OK is returned and the output variables populated as described 11294** above. 11295*/ 11296SQLITE_API int sqlite3changeset_pk( 11297 sqlite3_changeset_iter *pIter, /* Iterator object */ 11298 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */ 11299 int *pnCol /* OUT: Number of entries in output array */ 11300); 11301 11302/* 11303** CAPI3REF: Obtain old.* Values From A Changeset Iterator 11304** METHOD: sqlite3_changeset_iter 11305** 11306** The pIter argument passed to this function may either be an iterator 11307** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 11308** created by [sqlite3changeset_start()]. In the latter case, the most recent 11309** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 11310** Furthermore, it may only be called if the type of change that the iterator 11311** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise, 11312** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 11313** 11314** Argument iVal must be greater than or equal to 0, and less than the number 11315** of columns in the table affected by the current change. Otherwise, 11316** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 11317** 11318** If successful, this function sets *ppValue to point to a protected 11319** sqlite3_value object containing the iVal'th value from the vector of 11320** original row values stored as part of the UPDATE or DELETE change and 11321** returns SQLITE_OK. The name of the function comes from the fact that this 11322** is similar to the "old.*" columns available to update or delete triggers. 11323** 11324** If some other error occurs (e.g. an OOM condition), an SQLite error code 11325** is returned and *ppValue is set to NULL. 11326*/ 11327SQLITE_API int sqlite3changeset_old( 11328 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11329 int iVal, /* Column number */ 11330 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */ 11331); 11332 11333/* 11334** CAPI3REF: Obtain new.* Values From A Changeset Iterator 11335** METHOD: sqlite3_changeset_iter 11336** 11337** The pIter argument passed to this function may either be an iterator 11338** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator 11339** created by [sqlite3changeset_start()]. In the latter case, the most recent 11340** call to [sqlite3changeset_next()] must have returned SQLITE_ROW. 11341** Furthermore, it may only be called if the type of change that the iterator 11342** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise, 11343** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL. 11344** 11345** Argument iVal must be greater than or equal to 0, and less than the number 11346** of columns in the table affected by the current change. Otherwise, 11347** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 11348** 11349** If successful, this function sets *ppValue to point to a protected 11350** sqlite3_value object containing the iVal'th value from the vector of 11351** new row values stored as part of the UPDATE or INSERT change and 11352** returns SQLITE_OK. If the change is an UPDATE and does not include 11353** a new value for the requested column, *ppValue is set to NULL and 11354** SQLITE_OK returned. The name of the function comes from the fact that 11355** this is similar to the "new.*" columns available to update or delete 11356** triggers. 11357** 11358** If some other error occurs (e.g. an OOM condition), an SQLite error code 11359** is returned and *ppValue is set to NULL. 11360*/ 11361SQLITE_API int sqlite3changeset_new( 11362 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11363 int iVal, /* Column number */ 11364 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */ 11365); 11366 11367/* 11368** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator 11369** METHOD: sqlite3_changeset_iter 11370** 11371** This function should only be used with iterator objects passed to a 11372** conflict-handler callback by [sqlite3changeset_apply()] with either 11373** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function 11374** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue 11375** is set to NULL. 11376** 11377** Argument iVal must be greater than or equal to 0, and less than the number 11378** of columns in the table affected by the current change. Otherwise, 11379** [SQLITE_RANGE] is returned and *ppValue is set to NULL. 11380** 11381** If successful, this function sets *ppValue to point to a protected 11382** sqlite3_value object containing the iVal'th value from the 11383** "conflicting row" associated with the current conflict-handler callback 11384** and returns SQLITE_OK. 11385** 11386** If some other error occurs (e.g. an OOM condition), an SQLite error code 11387** is returned and *ppValue is set to NULL. 11388*/ 11389SQLITE_API int sqlite3changeset_conflict( 11390 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11391 int iVal, /* Column number */ 11392 sqlite3_value **ppValue /* OUT: Value from conflicting row */ 11393); 11394 11395/* 11396** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations 11397** METHOD: sqlite3_changeset_iter 11398** 11399** This function may only be called with an iterator passed to an 11400** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case 11401** it sets the output variable to the total number of known foreign key 11402** violations in the destination database and returns SQLITE_OK. 11403** 11404** In all other cases this function returns SQLITE_MISUSE. 11405*/ 11406SQLITE_API int sqlite3changeset_fk_conflicts( 11407 sqlite3_changeset_iter *pIter, /* Changeset iterator */ 11408 int *pnOut /* OUT: Number of FK violations */ 11409); 11410 11411 11412/* 11413** CAPI3REF: Finalize A Changeset Iterator 11414** METHOD: sqlite3_changeset_iter 11415** 11416** This function is used to finalize an iterator allocated with 11417** [sqlite3changeset_start()]. 11418** 11419** This function should only be called on iterators created using the 11420** [sqlite3changeset_start()] function. If an application calls this 11421** function with an iterator passed to a conflict-handler by 11422** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the 11423** call has no effect. 11424** 11425** If an error was encountered within a call to an sqlite3changeset_xxx() 11426** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an 11427** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding 11428** to that error is returned by this function. Otherwise, SQLITE_OK is 11429** returned. This is to allow the following pattern (pseudo-code): 11430** 11431** <pre> 11432** sqlite3changeset_start(); 11433** while( SQLITE_ROW==sqlite3changeset_next() ){ 11434** // Do something with change. 11435** } 11436** rc = sqlite3changeset_finalize(); 11437** if( rc!=SQLITE_OK ){ 11438** // An error has occurred 11439** } 11440** </pre> 11441*/ 11442SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter); 11443 11444/* 11445** CAPI3REF: Invert A Changeset 11446** 11447** This function is used to "invert" a changeset object. Applying an inverted 11448** changeset to a database reverses the effects of applying the uninverted 11449** changeset. Specifically: 11450** 11451** <ul> 11452** <li> Each DELETE change is changed to an INSERT, and 11453** <li> Each INSERT change is changed to a DELETE, and 11454** <li> For each UPDATE change, the old.* and new.* values are exchanged. 11455** </ul> 11456** 11457** This function does not change the order in which changes appear within 11458** the changeset. It merely reverses the sense of each individual change. 11459** 11460** If successful, a pointer to a buffer containing the inverted changeset 11461** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and 11462** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are 11463** zeroed and an SQLite error code returned. 11464** 11465** It is the responsibility of the caller to eventually call sqlite3_free() 11466** on the *ppOut pointer to free the buffer allocation following a successful 11467** call to this function. 11468** 11469** WARNING/TODO: This function currently assumes that the input is a valid 11470** changeset. If it is not, the results are undefined. 11471*/ 11472SQLITE_API int sqlite3changeset_invert( 11473 int nIn, const void *pIn, /* Input changeset */ 11474 int *pnOut, void **ppOut /* OUT: Inverse of input */ 11475); 11476 11477/* 11478** CAPI3REF: Concatenate Two Changeset Objects 11479** 11480** This function is used to concatenate two changesets, A and B, into a 11481** single changeset. The result is a changeset equivalent to applying 11482** changeset A followed by changeset B. 11483** 11484** This function combines the two input changesets using an 11485** sqlite3_changegroup object. Calling it produces similar results as the 11486** following code fragment: 11487** 11488** <pre> 11489** sqlite3_changegroup *pGrp; 11490** rc = sqlite3_changegroup_new(&pGrp); 11491** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA); 11492** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB); 11493** if( rc==SQLITE_OK ){ 11494** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut); 11495** }else{ 11496** *ppOut = 0; 11497** *pnOut = 0; 11498** } 11499** </pre> 11500** 11501** Refer to the sqlite3_changegroup documentation below for details. 11502*/ 11503SQLITE_API int sqlite3changeset_concat( 11504 int nA, /* Number of bytes in buffer pA */ 11505 void *pA, /* Pointer to buffer containing changeset A */ 11506 int nB, /* Number of bytes in buffer pB */ 11507 void *pB, /* Pointer to buffer containing changeset B */ 11508 int *pnOut, /* OUT: Number of bytes in output changeset */ 11509 void **ppOut /* OUT: Buffer containing output changeset */ 11510); 11511 11512 11513/* 11514** CAPI3REF: Changegroup Handle 11515** 11516** A changegroup is an object used to combine two or more 11517** [changesets] or [patchsets] 11518*/ 11519typedef struct sqlite3_changegroup sqlite3_changegroup; 11520 11521/* 11522** CAPI3REF: Create A New Changegroup Object 11523** CONSTRUCTOR: sqlite3_changegroup 11524** 11525** An sqlite3_changegroup object is used to combine two or more changesets 11526** (or patchsets) into a single changeset (or patchset). A single changegroup 11527** object may combine changesets or patchsets, but not both. The output is 11528** always in the same format as the input. 11529** 11530** If successful, this function returns SQLITE_OK and populates (*pp) with 11531** a pointer to a new sqlite3_changegroup object before returning. The caller 11532** should eventually free the returned object using a call to 11533** sqlite3changegroup_delete(). If an error occurs, an SQLite error code 11534** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL. 11535** 11536** The usual usage pattern for an sqlite3_changegroup object is as follows: 11537** 11538** <ul> 11539** <li> It is created using a call to sqlite3changegroup_new(). 11540** 11541** <li> Zero or more changesets (or patchsets) are added to the object 11542** by calling sqlite3changegroup_add(). 11543** 11544** <li> The result of combining all input changesets together is obtained 11545** by the application via a call to sqlite3changegroup_output(). 11546** 11547** <li> The object is deleted using a call to sqlite3changegroup_delete(). 11548** </ul> 11549** 11550** Any number of calls to add() and output() may be made between the calls to 11551** new() and delete(), and in any order. 11552** 11553** As well as the regular sqlite3changegroup_add() and 11554** sqlite3changegroup_output() functions, also available are the streaming 11555** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm(). 11556*/ 11557SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp); 11558 11559/* 11560** CAPI3REF: Add A Changeset To A Changegroup 11561** METHOD: sqlite3_changegroup 11562** 11563** Add all changes within the changeset (or patchset) in buffer pData (size 11564** nData bytes) to the changegroup. 11565** 11566** If the buffer contains a patchset, then all prior calls to this function 11567** on the same changegroup object must also have specified patchsets. Or, if 11568** the buffer contains a changeset, so must have the earlier calls to this 11569** function. Otherwise, SQLITE_ERROR is returned and no changes are added 11570** to the changegroup. 11571** 11572** Rows within the changeset and changegroup are identified by the values in 11573** their PRIMARY KEY columns. A change in the changeset is considered to 11574** apply to the same row as a change already present in the changegroup if 11575** the two rows have the same primary key. 11576** 11577** Changes to rows that do not already appear in the changegroup are 11578** simply copied into it. Or, if both the new changeset and the changegroup 11579** contain changes that apply to a single row, the final contents of the 11580** changegroup depends on the type of each change, as follows: 11581** 11582** <table border=1 style="margin-left:8ex;margin-right:8ex"> 11583** <tr><th style="white-space:pre">Existing Change </th> 11584** <th style="white-space:pre">New Change </th> 11585** <th>Output Change 11586** <tr><td>INSERT <td>INSERT <td> 11587** The new change is ignored. This case does not occur if the new 11588** changeset was recorded immediately after the changesets already 11589** added to the changegroup. 11590** <tr><td>INSERT <td>UPDATE <td> 11591** The INSERT change remains in the changegroup. The values in the 11592** INSERT change are modified as if the row was inserted by the 11593** existing change and then updated according to the new change. 11594** <tr><td>INSERT <td>DELETE <td> 11595** The existing INSERT is removed from the changegroup. The DELETE is 11596** not added. 11597** <tr><td>UPDATE <td>INSERT <td> 11598** The new change is ignored. This case does not occur if the new 11599** changeset was recorded immediately after the changesets already 11600** added to the changegroup. 11601** <tr><td>UPDATE <td>UPDATE <td> 11602** The existing UPDATE remains within the changegroup. It is amended 11603** so that the accompanying values are as if the row was updated once 11604** by the existing change and then again by the new change. 11605** <tr><td>UPDATE <td>DELETE <td> 11606** The existing UPDATE is replaced by the new DELETE within the 11607** changegroup. 11608** <tr><td>DELETE <td>INSERT <td> 11609** If one or more of the column values in the row inserted by the 11610** new change differ from those in the row deleted by the existing 11611** change, the existing DELETE is replaced by an UPDATE within the 11612** changegroup. Otherwise, if the inserted row is exactly the same 11613** as the deleted row, the existing DELETE is simply discarded. 11614** <tr><td>DELETE <td>UPDATE <td> 11615** The new change is ignored. This case does not occur if the new 11616** changeset was recorded immediately after the changesets already 11617** added to the changegroup. 11618** <tr><td>DELETE <td>DELETE <td> 11619** The new change is ignored. This case does not occur if the new 11620** changeset was recorded immediately after the changesets already 11621** added to the changegroup. 11622** </table> 11623** 11624** If the new changeset contains changes to a table that is already present 11625** in the changegroup, then the number of columns and the position of the 11626** primary key columns for the table must be consistent. If this is not the 11627** case, this function fails with SQLITE_SCHEMA. If the input changeset 11628** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is 11629** returned. Or, if an out-of-memory condition occurs during processing, this 11630** function returns SQLITE_NOMEM. In all cases, if an error occurs the state 11631** of the final contents of the changegroup is undefined. 11632** 11633** If no error occurs, SQLITE_OK is returned. 11634*/ 11635SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData); 11636 11637/* 11638** CAPI3REF: Obtain A Composite Changeset From A Changegroup 11639** METHOD: sqlite3_changegroup 11640** 11641** Obtain a buffer containing a changeset (or patchset) representing the 11642** current contents of the changegroup. If the inputs to the changegroup 11643** were themselves changesets, the output is a changeset. Or, if the 11644** inputs were patchsets, the output is also a patchset. 11645** 11646** As with the output of the sqlite3session_changeset() and 11647** sqlite3session_patchset() functions, all changes related to a single 11648** table are grouped together in the output of this function. Tables appear 11649** in the same order as for the very first changeset added to the changegroup. 11650** If the second or subsequent changesets added to the changegroup contain 11651** changes for tables that do not appear in the first changeset, they are 11652** appended onto the end of the output changeset, again in the order in 11653** which they are first encountered. 11654** 11655** If an error occurs, an SQLite error code is returned and the output 11656** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK 11657** is returned and the output variables are set to the size of and a 11658** pointer to the output buffer, respectively. In this case it is the 11659** responsibility of the caller to eventually free the buffer using a 11660** call to sqlite3_free(). 11661*/ 11662SQLITE_API int sqlite3changegroup_output( 11663 sqlite3_changegroup*, 11664 int *pnData, /* OUT: Size of output buffer in bytes */ 11665 void **ppData /* OUT: Pointer to output buffer */ 11666); 11667 11668/* 11669** CAPI3REF: Delete A Changegroup Object 11670** DESTRUCTOR: sqlite3_changegroup 11671*/ 11672SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*); 11673 11674/* 11675** CAPI3REF: Apply A Changeset To A Database 11676** 11677** Apply a changeset or patchset to a database. These functions attempt to 11678** update the "main" database attached to handle db with the changes found in 11679** the changeset passed via the second and third arguments. 11680** 11681** The fourth argument (xFilter) passed to these functions is the "filter 11682** callback". If it is not NULL, then for each table affected by at least one 11683** change in the changeset, the filter callback is invoked with 11684** the table name as the second argument, and a copy of the context pointer 11685** passed as the sixth argument as the first. If the "filter callback" 11686** returns zero, then no attempt is made to apply any changes to the table. 11687** Otherwise, if the return value is non-zero or the xFilter argument to 11688** is NULL, all changes related to the table are attempted. 11689** 11690** For each table that is not excluded by the filter callback, this function 11691** tests that the target database contains a compatible table. A table is 11692** considered compatible if all of the following are true: 11693** 11694** <ul> 11695** <li> The table has the same name as the name recorded in the 11696** changeset, and 11697** <li> The table has at least as many columns as recorded in the 11698** changeset, and 11699** <li> The table has primary key columns in the same position as 11700** recorded in the changeset. 11701** </ul> 11702** 11703** If there is no compatible table, it is not an error, but none of the 11704** changes associated with the table are applied. A warning message is issued 11705** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most 11706** one such warning is issued for each table in the changeset. 11707** 11708** For each change for which there is a compatible table, an attempt is made 11709** to modify the table contents according to the UPDATE, INSERT or DELETE 11710** change. If a change cannot be applied cleanly, the conflict handler 11711** function passed as the fifth argument to sqlite3changeset_apply() may be 11712** invoked. A description of exactly when the conflict handler is invoked for 11713** each type of change is below. 11714** 11715** Unlike the xFilter argument, xConflict may not be passed NULL. The results 11716** of passing anything other than a valid function pointer as the xConflict 11717** argument are undefined. 11718** 11719** Each time the conflict handler function is invoked, it must return one 11720** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or 11721** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned 11722** if the second argument passed to the conflict handler is either 11723** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler 11724** returns an illegal value, any changes already made are rolled back and 11725** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different 11726** actions are taken by sqlite3changeset_apply() depending on the value 11727** returned by each invocation of the conflict-handler function. Refer to 11728** the documentation for the three 11729** [SQLITE_CHANGESET_OMIT|available return values] for details. 11730** 11731** <dl> 11732** <dt>DELETE Changes<dd> 11733** For each DELETE change, the function checks if the target database 11734** contains a row with the same primary key value (or values) as the 11735** original row values stored in the changeset. If it does, and the values 11736** stored in all non-primary key columns also match the values stored in 11737** the changeset the row is deleted from the target database. 11738** 11739** If a row with matching primary key values is found, but one or more of 11740** the non-primary key fields contains a value different from the original 11741** row value stored in the changeset, the conflict-handler function is 11742** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the 11743** database table has more columns than are recorded in the changeset, 11744** only the values of those non-primary key fields are compared against 11745** the current database contents - any trailing database table columns 11746** are ignored. 11747** 11748** If no row with matching primary key values is found in the database, 11749** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 11750** passed as the second argument. 11751** 11752** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT 11753** (which can only happen if a foreign key constraint is violated), the 11754** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT] 11755** passed as the second argument. This includes the case where the DELETE 11756** operation is attempted because an earlier call to the conflict handler 11757** function returned [SQLITE_CHANGESET_REPLACE]. 11758** 11759** <dt>INSERT Changes<dd> 11760** For each INSERT change, an attempt is made to insert the new row into 11761** the database. If the changeset row contains fewer fields than the 11762** database table, the trailing fields are populated with their default 11763** values. 11764** 11765** If the attempt to insert the row fails because the database already 11766** contains a row with the same primary key values, the conflict handler 11767** function is invoked with the second argument set to 11768** [SQLITE_CHANGESET_CONFLICT]. 11769** 11770** If the attempt to insert the row fails because of some other constraint 11771** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is 11772** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT]. 11773** This includes the case where the INSERT operation is re-attempted because 11774** an earlier call to the conflict handler function returned 11775** [SQLITE_CHANGESET_REPLACE]. 11776** 11777** <dt>UPDATE Changes<dd> 11778** For each UPDATE change, the function checks if the target database 11779** contains a row with the same primary key value (or values) as the 11780** original row values stored in the changeset. If it does, and the values 11781** stored in all modified non-primary key columns also match the values 11782** stored in the changeset the row is updated within the target database. 11783** 11784** If a row with matching primary key values is found, but one or more of 11785** the modified non-primary key fields contains a value different from an 11786** original row value stored in the changeset, the conflict-handler function 11787** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since 11788** UPDATE changes only contain values for non-primary key fields that are 11789** to be modified, only those fields need to match the original values to 11790** avoid the SQLITE_CHANGESET_DATA conflict-handler callback. 11791** 11792** If no row with matching primary key values is found in the database, 11793** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND] 11794** passed as the second argument. 11795** 11796** If the UPDATE operation is attempted, but SQLite returns 11797** SQLITE_CONSTRAINT, the conflict-handler function is invoked with 11798** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument. 11799** This includes the case where the UPDATE operation is attempted after 11800** an earlier call to the conflict handler function returned 11801** [SQLITE_CHANGESET_REPLACE]. 11802** </dl> 11803** 11804** It is safe to execute SQL statements, including those that write to the 11805** table that the callback related to, from within the xConflict callback. 11806** This can be used to further customize the application's conflict 11807** resolution strategy. 11808** 11809** All changes made by these functions are enclosed in a savepoint transaction. 11810** If any other error (aside from a constraint failure when attempting to 11811** write to the target database) occurs, then the savepoint transaction is 11812** rolled back, restoring the target database to its original state, and an 11813** SQLite error code returned. 11814** 11815** If the output parameters (ppRebase) and (pnRebase) are non-NULL and 11816** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2() 11817** may set (*ppRebase) to point to a "rebase" that may be used with the 11818** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase) 11819** is set to the size of the buffer in bytes. It is the responsibility of the 11820** caller to eventually free any such buffer using sqlite3_free(). The buffer 11821** is only allocated and populated if one or more conflicts were encountered 11822** while applying the patchset. See comments surrounding the sqlite3_rebaser 11823** APIs for further details. 11824** 11825** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent 11826** may be modified by passing a combination of 11827** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter. 11828** 11829** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b> 11830** and therefore subject to change. 11831*/ 11832SQLITE_API int sqlite3changeset_apply( 11833 sqlite3 *db, /* Apply change to "main" db of this handle */ 11834 int nChangeset, /* Size of changeset in bytes */ 11835 void *pChangeset, /* Changeset blob */ 11836 int(*xFilter)( 11837 void *pCtx, /* Copy of sixth arg to _apply() */ 11838 const char *zTab /* Table name */ 11839 ), 11840 int(*xConflict)( 11841 void *pCtx, /* Copy of sixth arg to _apply() */ 11842 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11843 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11844 ), 11845 void *pCtx /* First argument passed to xConflict */ 11846); 11847SQLITE_API int sqlite3changeset_apply_v2( 11848 sqlite3 *db, /* Apply change to "main" db of this handle */ 11849 int nChangeset, /* Size of changeset in bytes */ 11850 void *pChangeset, /* Changeset blob */ 11851 int(*xFilter)( 11852 void *pCtx, /* Copy of sixth arg to _apply() */ 11853 const char *zTab /* Table name */ 11854 ), 11855 int(*xConflict)( 11856 void *pCtx, /* Copy of sixth arg to _apply() */ 11857 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 11858 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 11859 ), 11860 void *pCtx, /* First argument passed to xConflict */ 11861 void **ppRebase, int *pnRebase, /* OUT: Rebase data */ 11862 int flags /* SESSION_CHANGESETAPPLY_* flags */ 11863); 11864 11865/* 11866** CAPI3REF: Flags for sqlite3changeset_apply_v2 11867** 11868** The following flags may passed via the 9th parameter to 11869** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]: 11870** 11871** <dl> 11872** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd> 11873** Usually, the sessions module encloses all operations performed by 11874** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The 11875** SAVEPOINT is committed if the changeset or patchset is successfully 11876** applied, or rolled back if an error occurs. Specifying this flag 11877** causes the sessions module to omit this savepoint. In this case, if the 11878** caller has an open transaction or savepoint when apply_v2() is called, 11879** it may revert the partially applied changeset by rolling it back. 11880** 11881** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd> 11882** Invert the changeset before applying it. This is equivalent to inverting 11883** a changeset using sqlite3changeset_invert() before applying it. It is 11884** an error to specify this flag with a patchset. 11885*/ 11886#define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001 11887#define SQLITE_CHANGESETAPPLY_INVERT 0x0002 11888 11889/* 11890** CAPI3REF: Constants Passed To The Conflict Handler 11891** 11892** Values that may be passed as the second argument to a conflict-handler. 11893** 11894** <dl> 11895** <dt>SQLITE_CHANGESET_DATA<dd> 11896** The conflict handler is invoked with CHANGESET_DATA as the second argument 11897** when processing a DELETE or UPDATE change if a row with the required 11898** PRIMARY KEY fields is present in the database, but one or more other 11899** (non primary-key) fields modified by the update do not contain the 11900** expected "before" values. 11901** 11902** The conflicting row, in this case, is the database row with the matching 11903** primary key. 11904** 11905** <dt>SQLITE_CHANGESET_NOTFOUND<dd> 11906** The conflict handler is invoked with CHANGESET_NOTFOUND as the second 11907** argument when processing a DELETE or UPDATE change if a row with the 11908** required PRIMARY KEY fields is not present in the database. 11909** 11910** There is no conflicting row in this case. The results of invoking the 11911** sqlite3changeset_conflict() API are undefined. 11912** 11913** <dt>SQLITE_CHANGESET_CONFLICT<dd> 11914** CHANGESET_CONFLICT is passed as the second argument to the conflict 11915** handler while processing an INSERT change if the operation would result 11916** in duplicate primary key values. 11917** 11918** The conflicting row in this case is the database row with the matching 11919** primary key. 11920** 11921** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd> 11922** If foreign key handling is enabled, and applying a changeset leaves the 11923** database in a state containing foreign key violations, the conflict 11924** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument 11925** exactly once before the changeset is committed. If the conflict handler 11926** returns CHANGESET_OMIT, the changes, including those that caused the 11927** foreign key constraint violation, are committed. Or, if it returns 11928** CHANGESET_ABORT, the changeset is rolled back. 11929** 11930** No current or conflicting row information is provided. The only function 11931** it is possible to call on the supplied sqlite3_changeset_iter handle 11932** is sqlite3changeset_fk_conflicts(). 11933** 11934** <dt>SQLITE_CHANGESET_CONSTRAINT<dd> 11935** If any other constraint violation occurs while applying a change (i.e. 11936** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is 11937** invoked with CHANGESET_CONSTRAINT as the second argument. 11938** 11939** There is no conflicting row in this case. The results of invoking the 11940** sqlite3changeset_conflict() API are undefined. 11941** 11942** </dl> 11943*/ 11944#define SQLITE_CHANGESET_DATA 1 11945#define SQLITE_CHANGESET_NOTFOUND 2 11946#define SQLITE_CHANGESET_CONFLICT 3 11947#define SQLITE_CHANGESET_CONSTRAINT 4 11948#define SQLITE_CHANGESET_FOREIGN_KEY 5 11949 11950/* 11951** CAPI3REF: Constants Returned By The Conflict Handler 11952** 11953** A conflict handler callback must return one of the following three values. 11954** 11955** <dl> 11956** <dt>SQLITE_CHANGESET_OMIT<dd> 11957** If a conflict handler returns this value no special action is taken. The 11958** change that caused the conflict is not applied. The session module 11959** continues to the next change in the changeset. 11960** 11961** <dt>SQLITE_CHANGESET_REPLACE<dd> 11962** This value may only be returned if the second argument to the conflict 11963** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this 11964** is not the case, any changes applied so far are rolled back and the 11965** call to sqlite3changeset_apply() returns SQLITE_MISUSE. 11966** 11967** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict 11968** handler, then the conflicting row is either updated or deleted, depending 11969** on the type of change. 11970** 11971** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict 11972** handler, then the conflicting row is removed from the database and a 11973** second attempt to apply the change is made. If this second attempt fails, 11974** the original row is restored to the database before continuing. 11975** 11976** <dt>SQLITE_CHANGESET_ABORT<dd> 11977** If this value is returned, any changes applied so far are rolled back 11978** and the call to sqlite3changeset_apply() returns SQLITE_ABORT. 11979** </dl> 11980*/ 11981#define SQLITE_CHANGESET_OMIT 0 11982#define SQLITE_CHANGESET_REPLACE 1 11983#define SQLITE_CHANGESET_ABORT 2 11984 11985/* 11986** CAPI3REF: Rebasing changesets 11987** EXPERIMENTAL 11988** 11989** Suppose there is a site hosting a database in state S0. And that 11990** modifications are made that move that database to state S1 and a 11991** changeset recorded (the "local" changeset). Then, a changeset based 11992** on S0 is received from another site (the "remote" changeset) and 11993** applied to the database. The database is then in state 11994** (S1+"remote"), where the exact state depends on any conflict 11995** resolution decisions (OMIT or REPLACE) made while applying "remote". 11996** Rebasing a changeset is to update it to take those conflict 11997** resolution decisions into account, so that the same conflicts 11998** do not have to be resolved elsewhere in the network. 11999** 12000** For example, if both the local and remote changesets contain an 12001** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)": 12002** 12003** local: INSERT INTO t1 VALUES(1, 'v1'); 12004** remote: INSERT INTO t1 VALUES(1, 'v2'); 12005** 12006** and the conflict resolution is REPLACE, then the INSERT change is 12007** removed from the local changeset (it was overridden). Or, if the 12008** conflict resolution was "OMIT", then the local changeset is modified 12009** to instead contain: 12010** 12011** UPDATE t1 SET b = 'v2' WHERE a=1; 12012** 12013** Changes within the local changeset are rebased as follows: 12014** 12015** <dl> 12016** <dt>Local INSERT<dd> 12017** This may only conflict with a remote INSERT. If the conflict 12018** resolution was OMIT, then add an UPDATE change to the rebased 12019** changeset. Or, if the conflict resolution was REPLACE, add 12020** nothing to the rebased changeset. 12021** 12022** <dt>Local DELETE<dd> 12023** This may conflict with a remote UPDATE or DELETE. In both cases the 12024** only possible resolution is OMIT. If the remote operation was a 12025** DELETE, then add no change to the rebased changeset. If the remote 12026** operation was an UPDATE, then the old.* fields of change are updated 12027** to reflect the new.* values in the UPDATE. 12028** 12029** <dt>Local UPDATE<dd> 12030** This may conflict with a remote UPDATE or DELETE. If it conflicts 12031** with a DELETE, and the conflict resolution was OMIT, then the update 12032** is changed into an INSERT. Any undefined values in the new.* record 12033** from the update change are filled in using the old.* values from 12034** the conflicting DELETE. Or, if the conflict resolution was REPLACE, 12035** the UPDATE change is simply omitted from the rebased changeset. 12036** 12037** If conflict is with a remote UPDATE and the resolution is OMIT, then 12038** the old.* values are rebased using the new.* values in the remote 12039** change. Or, if the resolution is REPLACE, then the change is copied 12040** into the rebased changeset with updates to columns also updated by 12041** the conflicting remote UPDATE removed. If this means no columns would 12042** be updated, the change is omitted. 12043** </dl> 12044** 12045** A local change may be rebased against multiple remote changes 12046** simultaneously. If a single key is modified by multiple remote 12047** changesets, they are combined as follows before the local changeset 12048** is rebased: 12049** 12050** <ul> 12051** <li> If there has been one or more REPLACE resolutions on a 12052** key, it is rebased according to a REPLACE. 12053** 12054** <li> If there have been no REPLACE resolutions on a key, then 12055** the local changeset is rebased according to the most recent 12056** of the OMIT resolutions. 12057** </ul> 12058** 12059** Note that conflict resolutions from multiple remote changesets are 12060** combined on a per-field basis, not per-row. This means that in the 12061** case of multiple remote UPDATE operations, some fields of a single 12062** local change may be rebased for REPLACE while others are rebased for 12063** OMIT. 12064** 12065** In order to rebase a local changeset, the remote changeset must first 12066** be applied to the local database using sqlite3changeset_apply_v2() and 12067** the buffer of rebase information captured. Then: 12068** 12069** <ol> 12070** <li> An sqlite3_rebaser object is created by calling 12071** sqlite3rebaser_create(). 12072** <li> The new object is configured with the rebase buffer obtained from 12073** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure(). 12074** If the local changeset is to be rebased against multiple remote 12075** changesets, then sqlite3rebaser_configure() should be called 12076** multiple times, in the same order that the multiple 12077** sqlite3changeset_apply_v2() calls were made. 12078** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase(). 12079** <li> The sqlite3_rebaser object is deleted by calling 12080** sqlite3rebaser_delete(). 12081** </ol> 12082*/ 12083typedef struct sqlite3_rebaser sqlite3_rebaser; 12084 12085/* 12086** CAPI3REF: Create a changeset rebaser object. 12087** EXPERIMENTAL 12088** 12089** Allocate a new changeset rebaser object. If successful, set (*ppNew) to 12090** point to the new object and return SQLITE_OK. Otherwise, if an error 12091** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew) 12092** to NULL. 12093*/ 12094SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew); 12095 12096/* 12097** CAPI3REF: Configure a changeset rebaser object. 12098** EXPERIMENTAL 12099** 12100** Configure the changeset rebaser object to rebase changesets according 12101** to the conflict resolutions described by buffer pRebase (size nRebase 12102** bytes), which must have been obtained from a previous call to 12103** sqlite3changeset_apply_v2(). 12104*/ 12105SQLITE_API int sqlite3rebaser_configure( 12106 sqlite3_rebaser*, 12107 int nRebase, const void *pRebase 12108); 12109 12110/* 12111** CAPI3REF: Rebase a changeset 12112** EXPERIMENTAL 12113** 12114** Argument pIn must point to a buffer containing a changeset nIn bytes 12115** in size. This function allocates and populates a buffer with a copy 12116** of the changeset rebased according to the configuration of the 12117** rebaser object passed as the first argument. If successful, (*ppOut) 12118** is set to point to the new buffer containing the rebased changeset and 12119** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the 12120** responsibility of the caller to eventually free the new buffer using 12121** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut) 12122** are set to zero and an SQLite error code returned. 12123*/ 12124SQLITE_API int sqlite3rebaser_rebase( 12125 sqlite3_rebaser*, 12126 int nIn, const void *pIn, 12127 int *pnOut, void **ppOut 12128); 12129 12130/* 12131** CAPI3REF: Delete a changeset rebaser object. 12132** EXPERIMENTAL 12133** 12134** Delete the changeset rebaser object and all associated resources. There 12135** should be one call to this function for each successful invocation 12136** of sqlite3rebaser_create(). 12137*/ 12138SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p); 12139 12140/* 12141** CAPI3REF: Streaming Versions of API functions. 12142** 12143** The six streaming API xxx_strm() functions serve similar purposes to the 12144** corresponding non-streaming API functions: 12145** 12146** <table border=1 style="margin-left:8ex;margin-right:8ex"> 12147** <tr><th>Streaming function<th>Non-streaming equivalent</th> 12148** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply] 12149** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2] 12150** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat] 12151** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert] 12152** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start] 12153** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset] 12154** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset] 12155** </table> 12156** 12157** Non-streaming functions that accept changesets (or patchsets) as input 12158** require that the entire changeset be stored in a single buffer in memory. 12159** Similarly, those that return a changeset or patchset do so by returning 12160** a pointer to a single large buffer allocated using sqlite3_malloc(). 12161** Normally this is convenient. However, if an application running in a 12162** low-memory environment is required to handle very large changesets, the 12163** large contiguous memory allocations required can become onerous. 12164** 12165** In order to avoid this problem, instead of a single large buffer, input 12166** is passed to a streaming API functions by way of a callback function that 12167** the sessions module invokes to incrementally request input data as it is 12168** required. In all cases, a pair of API function parameters such as 12169** 12170** <pre> 12171** int nChangeset, 12172** void *pChangeset, 12173** </pre> 12174** 12175** Is replaced by: 12176** 12177** <pre> 12178** int (*xInput)(void *pIn, void *pData, int *pnData), 12179** void *pIn, 12180** </pre> 12181** 12182** Each time the xInput callback is invoked by the sessions module, the first 12183** argument passed is a copy of the supplied pIn context pointer. The second 12184** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no 12185** error occurs the xInput method should copy up to (*pnData) bytes of data 12186** into the buffer and set (*pnData) to the actual number of bytes copied 12187** before returning SQLITE_OK. If the input is completely exhausted, (*pnData) 12188** should be set to zero to indicate this. Or, if an error occurs, an SQLite 12189** error code should be returned. In all cases, if an xInput callback returns 12190** an error, all processing is abandoned and the streaming API function 12191** returns a copy of the error code to the caller. 12192** 12193** In the case of sqlite3changeset_start_strm(), the xInput callback may be 12194** invoked by the sessions module at any point during the lifetime of the 12195** iterator. If such an xInput callback returns an error, the iterator enters 12196** an error state, whereby all subsequent calls to iterator functions 12197** immediately fail with the same error code as returned by xInput. 12198** 12199** Similarly, streaming API functions that return changesets (or patchsets) 12200** return them in chunks by way of a callback function instead of via a 12201** pointer to a single large buffer. In this case, a pair of parameters such 12202** as: 12203** 12204** <pre> 12205** int *pnChangeset, 12206** void **ppChangeset, 12207** </pre> 12208** 12209** Is replaced by: 12210** 12211** <pre> 12212** int (*xOutput)(void *pOut, const void *pData, int nData), 12213** void *pOut 12214** </pre> 12215** 12216** The xOutput callback is invoked zero or more times to return data to 12217** the application. The first parameter passed to each call is a copy of the 12218** pOut pointer supplied by the application. The second parameter, pData, 12219** points to a buffer nData bytes in size containing the chunk of output 12220** data being returned. If the xOutput callback successfully processes the 12221** supplied data, it should return SQLITE_OK to indicate success. Otherwise, 12222** it should return some other SQLite error code. In this case processing 12223** is immediately abandoned and the streaming API function returns a copy 12224** of the xOutput error code to the application. 12225** 12226** The sessions module never invokes an xOutput callback with the third 12227** parameter set to a value less than or equal to zero. Other than this, 12228** no guarantees are made as to the size of the chunks of data returned. 12229*/ 12230SQLITE_API int sqlite3changeset_apply_strm( 12231 sqlite3 *db, /* Apply change to "main" db of this handle */ 12232 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 12233 void *pIn, /* First arg for xInput */ 12234 int(*xFilter)( 12235 void *pCtx, /* Copy of sixth arg to _apply() */ 12236 const char *zTab /* Table name */ 12237 ), 12238 int(*xConflict)( 12239 void *pCtx, /* Copy of sixth arg to _apply() */ 12240 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 12241 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 12242 ), 12243 void *pCtx /* First argument passed to xConflict */ 12244); 12245SQLITE_API int sqlite3changeset_apply_v2_strm( 12246 sqlite3 *db, /* Apply change to "main" db of this handle */ 12247 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */ 12248 void *pIn, /* First arg for xInput */ 12249 int(*xFilter)( 12250 void *pCtx, /* Copy of sixth arg to _apply() */ 12251 const char *zTab /* Table name */ 12252 ), 12253 int(*xConflict)( 12254 void *pCtx, /* Copy of sixth arg to _apply() */ 12255 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */ 12256 sqlite3_changeset_iter *p /* Handle describing change and conflict */ 12257 ), 12258 void *pCtx, /* First argument passed to xConflict */ 12259 void **ppRebase, int *pnRebase, 12260 int flags 12261); 12262SQLITE_API int sqlite3changeset_concat_strm( 12263 int (*xInputA)(void *pIn, void *pData, int *pnData), 12264 void *pInA, 12265 int (*xInputB)(void *pIn, void *pData, int *pnData), 12266 void *pInB, 12267 int (*xOutput)(void *pOut, const void *pData, int nData), 12268 void *pOut 12269); 12270SQLITE_API int sqlite3changeset_invert_strm( 12271 int (*xInput)(void *pIn, void *pData, int *pnData), 12272 void *pIn, 12273 int (*xOutput)(void *pOut, const void *pData, int nData), 12274 void *pOut 12275); 12276SQLITE_API int sqlite3changeset_start_strm( 12277 sqlite3_changeset_iter **pp, 12278 int (*xInput)(void *pIn, void *pData, int *pnData), 12279 void *pIn 12280); 12281SQLITE_API int sqlite3changeset_start_v2_strm( 12282 sqlite3_changeset_iter **pp, 12283 int (*xInput)(void *pIn, void *pData, int *pnData), 12284 void *pIn, 12285 int flags 12286); 12287SQLITE_API int sqlite3session_changeset_strm( 12288 sqlite3_session *pSession, 12289 int (*xOutput)(void *pOut, const void *pData, int nData), 12290 void *pOut 12291); 12292SQLITE_API int sqlite3session_patchset_strm( 12293 sqlite3_session *pSession, 12294 int (*xOutput)(void *pOut, const void *pData, int nData), 12295 void *pOut 12296); 12297SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*, 12298 int (*xInput)(void *pIn, void *pData, int *pnData), 12299 void *pIn 12300); 12301SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*, 12302 int (*xOutput)(void *pOut, const void *pData, int nData), 12303 void *pOut 12304); 12305SQLITE_API int sqlite3rebaser_rebase_strm( 12306 sqlite3_rebaser *pRebaser, 12307 int (*xInput)(void *pIn, void *pData, int *pnData), 12308 void *pIn, 12309 int (*xOutput)(void *pOut, const void *pData, int nData), 12310 void *pOut 12311); 12312 12313/* 12314** CAPI3REF: Configure global parameters 12315** 12316** The sqlite3session_config() interface is used to make global configuration 12317** changes to the sessions module in order to tune it to the specific needs 12318** of the application. 12319** 12320** The sqlite3session_config() interface is not threadsafe. If it is invoked 12321** while any other thread is inside any other sessions method then the 12322** results are undefined. Furthermore, if it is invoked after any sessions 12323** related objects have been created, the results are also undefined. 12324** 12325** The first argument to the sqlite3session_config() function must be one 12326** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The 12327** interpretation of the (void*) value passed as the second parameter and 12328** the effect of calling this function depends on the value of the first 12329** parameter. 12330** 12331** <dl> 12332** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd> 12333** By default, the sessions module streaming interfaces attempt to input 12334** and output data in approximately 1 KiB chunks. This operand may be used 12335** to set and query the value of this configuration setting. The pointer 12336** passed as the second argument must point to a value of type (int). 12337** If this value is greater than 0, it is used as the new streaming data 12338** chunk size for both input and output. Before returning, the (int) value 12339** pointed to by pArg is set to the final value of the streaming interface 12340** chunk size. 12341** </dl> 12342** 12343** This function returns SQLITE_OK if successful, or an SQLite error code 12344** otherwise. 12345*/ 12346SQLITE_API int sqlite3session_config(int op, void *pArg); 12347 12348/* 12349** CAPI3REF: Values for sqlite3session_config(). 12350*/ 12351#define SQLITE_SESSION_CONFIG_STRMSIZE 1 12352 12353/* 12354** Make sure we can call this stuff from C++. 12355*/ 12356#ifdef __cplusplus 12357} 12358#endif 12359 12360#endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */ 12361 12362/******** End of sqlite3session.h *********/ 12363/******** Begin file fts5.h *********/ 12364/* 12365** 2014 May 31 12366** 12367** The author disclaims copyright to this source code. In place of 12368** a legal notice, here is a blessing: 12369** 12370** May you do good and not evil. 12371** May you find forgiveness for yourself and forgive others. 12372** May you share freely, never taking more than you give. 12373** 12374****************************************************************************** 12375** 12376** Interfaces to extend FTS5. Using the interfaces defined in this file, 12377** FTS5 may be extended with: 12378** 12379** * custom tokenizers, and 12380** * custom auxiliary functions. 12381*/ 12382 12383 12384#ifndef _FTS5_H 12385#define _FTS5_H 12386 12387 12388#ifdef __cplusplus 12389extern "C" { 12390#endif 12391 12392/************************************************************************* 12393** CUSTOM AUXILIARY FUNCTIONS 12394** 12395** Virtual table implementations may overload SQL functions by implementing 12396** the sqlite3_module.xFindFunction() method. 12397*/ 12398 12399typedef struct Fts5ExtensionApi Fts5ExtensionApi; 12400typedef struct Fts5Context Fts5Context; 12401typedef struct Fts5PhraseIter Fts5PhraseIter; 12402 12403typedef void (*fts5_extension_function)( 12404 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */ 12405 Fts5Context *pFts, /* First arg to pass to pApi functions */ 12406 sqlite3_context *pCtx, /* Context for returning result/error */ 12407 int nVal, /* Number of values in apVal[] array */ 12408 sqlite3_value **apVal /* Array of trailing arguments */ 12409); 12410 12411struct Fts5PhraseIter { 12412 const unsigned char *a; 12413 const unsigned char *b; 12414}; 12415 12416/* 12417** EXTENSION API FUNCTIONS 12418** 12419** xUserData(pFts): 12420** Return a copy of the context pointer the extension function was 12421** registered with. 12422** 12423** xColumnTotalSize(pFts, iCol, pnToken): 12424** If parameter iCol is less than zero, set output variable *pnToken 12425** to the total number of tokens in the FTS5 table. Or, if iCol is 12426** non-negative but less than the number of columns in the table, return 12427** the total number of tokens in column iCol, considering all rows in 12428** the FTS5 table. 12429** 12430** If parameter iCol is greater than or equal to the number of columns 12431** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 12432** an OOM condition or IO error), an appropriate SQLite error code is 12433** returned. 12434** 12435** xColumnCount(pFts): 12436** Return the number of columns in the table. 12437** 12438** xColumnSize(pFts, iCol, pnToken): 12439** If parameter iCol is less than zero, set output variable *pnToken 12440** to the total number of tokens in the current row. Or, if iCol is 12441** non-negative but less than the number of columns in the table, set 12442** *pnToken to the number of tokens in column iCol of the current row. 12443** 12444** If parameter iCol is greater than or equal to the number of columns 12445** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g. 12446** an OOM condition or IO error), an appropriate SQLite error code is 12447** returned. 12448** 12449** This function may be quite inefficient if used with an FTS5 table 12450** created with the "columnsize=0" option. 12451** 12452** xColumnText: 12453** This function attempts to retrieve the text of column iCol of the 12454** current document. If successful, (*pz) is set to point to a buffer 12455** containing the text in utf-8 encoding, (*pn) is set to the size in bytes 12456** (not characters) of the buffer and SQLITE_OK is returned. Otherwise, 12457** if an error occurs, an SQLite error code is returned and the final values 12458** of (*pz) and (*pn) are undefined. 12459** 12460** xPhraseCount: 12461** Returns the number of phrases in the current query expression. 12462** 12463** xPhraseSize: 12464** Returns the number of tokens in phrase iPhrase of the query. Phrases 12465** are numbered starting from zero. 12466** 12467** xInstCount: 12468** Set *pnInst to the total number of occurrences of all phrases within 12469** the query within the current row. Return SQLITE_OK if successful, or 12470** an error code (i.e. SQLITE_NOMEM) if an error occurs. 12471** 12472** This API can be quite slow if used with an FTS5 table created with the 12473** "detail=none" or "detail=column" option. If the FTS5 table is created 12474** with either "detail=none" or "detail=column" and "content=" option 12475** (i.e. if it is a contentless table), then this API always returns 0. 12476** 12477** xInst: 12478** Query for the details of phrase match iIdx within the current row. 12479** Phrase matches are numbered starting from zero, so the iIdx argument 12480** should be greater than or equal to zero and smaller than the value 12481** output by xInstCount(). 12482** 12483** Usually, output parameter *piPhrase is set to the phrase number, *piCol 12484** to the column in which it occurs and *piOff the token offset of the 12485** first token of the phrase. Returns SQLITE_OK if successful, or an error 12486** code (i.e. SQLITE_NOMEM) if an error occurs. 12487** 12488** This API can be quite slow if used with an FTS5 table created with the 12489** "detail=none" or "detail=column" option. 12490** 12491** xRowid: 12492** Returns the rowid of the current row. 12493** 12494** xTokenize: 12495** Tokenize text using the tokenizer belonging to the FTS5 table. 12496** 12497** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback): 12498** This API function is used to query the FTS table for phrase iPhrase 12499** of the current query. Specifically, a query equivalent to: 12500** 12501** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid 12502** 12503** with $p set to a phrase equivalent to the phrase iPhrase of the 12504** current query is executed. Any column filter that applies to 12505** phrase iPhrase of the current query is included in $p. For each 12506** row visited, the callback function passed as the fourth argument 12507** is invoked. The context and API objects passed to the callback 12508** function may be used to access the properties of each matched row. 12509** Invoking Api.xUserData() returns a copy of the pointer passed as 12510** the third argument to pUserData. 12511** 12512** If the callback function returns any value other than SQLITE_OK, the 12513** query is abandoned and the xQueryPhrase function returns immediately. 12514** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK. 12515** Otherwise, the error code is propagated upwards. 12516** 12517** If the query runs to completion without incident, SQLITE_OK is returned. 12518** Or, if some error occurs before the query completes or is aborted by 12519** the callback, an SQLite error code is returned. 12520** 12521** 12522** xSetAuxdata(pFts5, pAux, xDelete) 12523** 12524** Save the pointer passed as the second argument as the extension function's 12525** "auxiliary data". The pointer may then be retrieved by the current or any 12526** future invocation of the same fts5 extension function made as part of 12527** the same MATCH query using the xGetAuxdata() API. 12528** 12529** Each extension function is allocated a single auxiliary data slot for 12530** each FTS query (MATCH expression). If the extension function is invoked 12531** more than once for a single FTS query, then all invocations share a 12532** single auxiliary data context. 12533** 12534** If there is already an auxiliary data pointer when this function is 12535** invoked, then it is replaced by the new pointer. If an xDelete callback 12536** was specified along with the original pointer, it is invoked at this 12537** point. 12538** 12539** The xDelete callback, if one is specified, is also invoked on the 12540** auxiliary data pointer after the FTS5 query has finished. 12541** 12542** If an error (e.g. an OOM condition) occurs within this function, 12543** the auxiliary data is set to NULL and an error code returned. If the 12544** xDelete parameter was not NULL, it is invoked on the auxiliary data 12545** pointer before returning. 12546** 12547** 12548** xGetAuxdata(pFts5, bClear) 12549** 12550** Returns the current auxiliary data pointer for the fts5 extension 12551** function. See the xSetAuxdata() method for details. 12552** 12553** If the bClear argument is non-zero, then the auxiliary data is cleared 12554** (set to NULL) before this function returns. In this case the xDelete, 12555** if any, is not invoked. 12556** 12557** 12558** xRowCount(pFts5, pnRow) 12559** 12560** This function is used to retrieve the total number of rows in the table. 12561** In other words, the same value that would be returned by: 12562** 12563** SELECT count(*) FROM ftstable; 12564** 12565** xPhraseFirst() 12566** This function is used, along with type Fts5PhraseIter and the xPhraseNext 12567** method, to iterate through all instances of a single query phrase within 12568** the current row. This is the same information as is accessible via the 12569** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient 12570** to use, this API may be faster under some circumstances. To iterate 12571** through instances of phrase iPhrase, use the following code: 12572** 12573** Fts5PhraseIter iter; 12574** int iCol, iOff; 12575** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff); 12576** iCol>=0; 12577** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff) 12578** ){ 12579** // An instance of phrase iPhrase at offset iOff of column iCol 12580** } 12581** 12582** The Fts5PhraseIter structure is defined above. Applications should not 12583** modify this structure directly - it should only be used as shown above 12584** with the xPhraseFirst() and xPhraseNext() API methods (and by 12585** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below). 12586** 12587** This API can be quite slow if used with an FTS5 table created with the 12588** "detail=none" or "detail=column" option. If the FTS5 table is created 12589** with either "detail=none" or "detail=column" and "content=" option 12590** (i.e. if it is a contentless table), then this API always iterates 12591** through an empty set (all calls to xPhraseFirst() set iCol to -1). 12592** 12593** xPhraseNext() 12594** See xPhraseFirst above. 12595** 12596** xPhraseFirstColumn() 12597** This function and xPhraseNextColumn() are similar to the xPhraseFirst() 12598** and xPhraseNext() APIs described above. The difference is that instead 12599** of iterating through all instances of a phrase in the current row, these 12600** APIs are used to iterate through the set of columns in the current row 12601** that contain one or more instances of a specified phrase. For example: 12602** 12603** Fts5PhraseIter iter; 12604** int iCol; 12605** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol); 12606** iCol>=0; 12607** pApi->xPhraseNextColumn(pFts, &iter, &iCol) 12608** ){ 12609** // Column iCol contains at least one instance of phrase iPhrase 12610** } 12611** 12612** This API can be quite slow if used with an FTS5 table created with the 12613** "detail=none" option. If the FTS5 table is created with either 12614** "detail=none" "content=" option (i.e. if it is a contentless table), 12615** then this API always iterates through an empty set (all calls to 12616** xPhraseFirstColumn() set iCol to -1). 12617** 12618** The information accessed using this API and its companion 12619** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext 12620** (or xInst/xInstCount). The chief advantage of this API is that it is 12621** significantly more efficient than those alternatives when used with 12622** "detail=column" tables. 12623** 12624** xPhraseNextColumn() 12625** See xPhraseFirstColumn above. 12626*/ 12627struct Fts5ExtensionApi { 12628 int iVersion; /* Currently always set to 3 */ 12629 12630 void *(*xUserData)(Fts5Context*); 12631 12632 int (*xColumnCount)(Fts5Context*); 12633 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow); 12634 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken); 12635 12636 int (*xTokenize)(Fts5Context*, 12637 const char *pText, int nText, /* Text to tokenize */ 12638 void *pCtx, /* Context passed to xToken() */ 12639 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */ 12640 ); 12641 12642 int (*xPhraseCount)(Fts5Context*); 12643 int (*xPhraseSize)(Fts5Context*, int iPhrase); 12644 12645 int (*xInstCount)(Fts5Context*, int *pnInst); 12646 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff); 12647 12648 sqlite3_int64 (*xRowid)(Fts5Context*); 12649 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn); 12650 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken); 12651 12652 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData, 12653 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*) 12654 ); 12655 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*)); 12656 void *(*xGetAuxdata)(Fts5Context*, int bClear); 12657 12658 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*); 12659 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff); 12660 12661 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*); 12662 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol); 12663}; 12664 12665/* 12666** CUSTOM AUXILIARY FUNCTIONS 12667*************************************************************************/ 12668 12669/************************************************************************* 12670** CUSTOM TOKENIZERS 12671** 12672** Applications may also register custom tokenizer types. A tokenizer 12673** is registered by providing fts5 with a populated instance of the 12674** following structure. All structure methods must be defined, setting 12675** any member of the fts5_tokenizer struct to NULL leads to undefined 12676** behaviour. The structure methods are expected to function as follows: 12677** 12678** xCreate: 12679** This function is used to allocate and initialize a tokenizer instance. 12680** A tokenizer instance is required to actually tokenize text. 12681** 12682** The first argument passed to this function is a copy of the (void*) 12683** pointer provided by the application when the fts5_tokenizer object 12684** was registered with FTS5 (the third argument to xCreateTokenizer()). 12685** The second and third arguments are an array of nul-terminated strings 12686** containing the tokenizer arguments, if any, specified following the 12687** tokenizer name as part of the CREATE VIRTUAL TABLE statement used 12688** to create the FTS5 table. 12689** 12690** The final argument is an output variable. If successful, (*ppOut) 12691** should be set to point to the new tokenizer handle and SQLITE_OK 12692** returned. If an error occurs, some value other than SQLITE_OK should 12693** be returned. In this case, fts5 assumes that the final value of *ppOut 12694** is undefined. 12695** 12696** xDelete: 12697** This function is invoked to delete a tokenizer handle previously 12698** allocated using xCreate(). Fts5 guarantees that this function will 12699** be invoked exactly once for each successful call to xCreate(). 12700** 12701** xTokenize: 12702** This function is expected to tokenize the nText byte string indicated 12703** by argument pText. pText may or may not be nul-terminated. The first 12704** argument passed to this function is a pointer to an Fts5Tokenizer object 12705** returned by an earlier call to xCreate(). 12706** 12707** The second argument indicates the reason that FTS5 is requesting 12708** tokenization of the supplied text. This is always one of the following 12709** four values: 12710** 12711** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into 12712** or removed from the FTS table. The tokenizer is being invoked to 12713** determine the set of tokens to add to (or delete from) the 12714** FTS index. 12715** 12716** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed 12717** against the FTS index. The tokenizer is being called to tokenize 12718** a bareword or quoted string specified as part of the query. 12719** 12720** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as 12721** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is 12722** followed by a "*" character, indicating that the last token 12723** returned by the tokenizer will be treated as a token prefix. 12724** 12725** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to 12726** satisfy an fts5_api.xTokenize() request made by an auxiliary 12727** function. Or an fts5_api.xColumnSize() request made by the same 12728** on a columnsize=0 database. 12729** </ul> 12730** 12731** For each token in the input string, the supplied callback xToken() must 12732** be invoked. The first argument to it should be a copy of the pointer 12733** passed as the second argument to xTokenize(). The third and fourth 12734** arguments are a pointer to a buffer containing the token text, and the 12735** size of the token in bytes. The 4th and 5th arguments are the byte offsets 12736** of the first byte of and first byte immediately following the text from 12737** which the token is derived within the input. 12738** 12739** The second argument passed to the xToken() callback ("tflags") should 12740** normally be set to 0. The exception is if the tokenizer supports 12741** synonyms. In this case see the discussion below for details. 12742** 12743** FTS5 assumes the xToken() callback is invoked for each token in the 12744** order that they occur within the input text. 12745** 12746** If an xToken() callback returns any value other than SQLITE_OK, then 12747** the tokenization should be abandoned and the xTokenize() method should 12748** immediately return a copy of the xToken() return value. Or, if the 12749** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally, 12750** if an error occurs with the xTokenize() implementation itself, it 12751** may abandon the tokenization and return any error code other than 12752** SQLITE_OK or SQLITE_DONE. 12753** 12754** SYNONYM SUPPORT 12755** 12756** Custom tokenizers may also support synonyms. Consider a case in which a 12757** user wishes to query for a phrase such as "first place". Using the 12758** built-in tokenizers, the FTS5 query 'first + place' will match instances 12759** of "first place" within the document set, but not alternative forms 12760** such as "1st place". In some applications, it would be better to match 12761** all instances of "first place" or "1st place" regardless of which form 12762** the user specified in the MATCH query text. 12763** 12764** There are several ways to approach this in FTS5: 12765** 12766** <ol><li> By mapping all synonyms to a single token. In this case, using 12767** the above example, this means that the tokenizer returns the 12768** same token for inputs "first" and "1st". Say that token is in 12769** fact "first", so that when the user inserts the document "I won 12770** 1st place" entries are added to the index for tokens "i", "won", 12771** "first" and "place". If the user then queries for '1st + place', 12772** the tokenizer substitutes "first" for "1st" and the query works 12773** as expected. 12774** 12775** <li> By querying the index for all synonyms of each query term 12776** separately. In this case, when tokenizing query text, the 12777** tokenizer may provide multiple synonyms for a single term 12778** within the document. FTS5 then queries the index for each 12779** synonym individually. For example, faced with the query: 12780** 12781** <codeblock> 12782** ... MATCH 'first place'</codeblock> 12783** 12784** the tokenizer offers both "1st" and "first" as synonyms for the 12785** first token in the MATCH query and FTS5 effectively runs a query 12786** similar to: 12787** 12788** <codeblock> 12789** ... MATCH '(first OR 1st) place'</codeblock> 12790** 12791** except that, for the purposes of auxiliary functions, the query 12792** still appears to contain just two phrases - "(first OR 1st)" 12793** being treated as a single phrase. 12794** 12795** <li> By adding multiple synonyms for a single term to the FTS index. 12796** Using this method, when tokenizing document text, the tokenizer 12797** provides multiple synonyms for each token. So that when a 12798** document such as "I won first place" is tokenized, entries are 12799** added to the FTS index for "i", "won", "first", "1st" and 12800** "place". 12801** 12802** This way, even if the tokenizer does not provide synonyms 12803** when tokenizing query text (it should not - to do so would be 12804** inefficient), it doesn't matter if the user queries for 12805** 'first + place' or '1st + place', as there are entries in the 12806** FTS index corresponding to both forms of the first token. 12807** </ol> 12808** 12809** Whether it is parsing document or query text, any call to xToken that 12810** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit 12811** is considered to supply a synonym for the previous token. For example, 12812** when parsing the document "I won first place", a tokenizer that supports 12813** synonyms would call xToken() 5 times, as follows: 12814** 12815** <codeblock> 12816** xToken(pCtx, 0, "i", 1, 0, 1); 12817** xToken(pCtx, 0, "won", 3, 2, 5); 12818** xToken(pCtx, 0, "first", 5, 6, 11); 12819** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11); 12820** xToken(pCtx, 0, "place", 5, 12, 17); 12821**</codeblock> 12822** 12823** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time 12824** xToken() is called. Multiple synonyms may be specified for a single token 12825** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence. 12826** There is no limit to the number of synonyms that may be provided for a 12827** single token. 12828** 12829** In many cases, method (1) above is the best approach. It does not add 12830** extra data to the FTS index or require FTS5 to query for multiple terms, 12831** so it is efficient in terms of disk space and query speed. However, it 12832** does not support prefix queries very well. If, as suggested above, the 12833** token "first" is substituted for "1st" by the tokenizer, then the query: 12834** 12835** <codeblock> 12836** ... MATCH '1s*'</codeblock> 12837** 12838** will not match documents that contain the token "1st" (as the tokenizer 12839** will probably not map "1s" to any prefix of "first"). 12840** 12841** For full prefix support, method (3) may be preferred. In this case, 12842** because the index contains entries for both "first" and "1st", prefix 12843** queries such as 'fi*' or '1s*' will match correctly. However, because 12844** extra entries are added to the FTS index, this method uses more space 12845** within the database. 12846** 12847** Method (2) offers a midpoint between (1) and (3). Using this method, 12848** a query such as '1s*' will match documents that contain the literal 12849** token "1st", but not "first" (assuming the tokenizer is not able to 12850** provide synonyms for prefixes). However, a non-prefix query like '1st' 12851** will match against "1st" and "first". This method does not require 12852** extra disk space, as no extra entries are added to the FTS index. 12853** On the other hand, it may require more CPU cycles to run MATCH queries, 12854** as separate queries of the FTS index are required for each synonym. 12855** 12856** When using methods (2) or (3), it is important that the tokenizer only 12857** provide synonyms when tokenizing document text (method (2)) or query 12858** text (method (3)), not both. Doing so will not cause any errors, but is 12859** inefficient. 12860*/ 12861typedef struct Fts5Tokenizer Fts5Tokenizer; 12862typedef struct fts5_tokenizer fts5_tokenizer; 12863struct fts5_tokenizer { 12864 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut); 12865 void (*xDelete)(Fts5Tokenizer*); 12866 int (*xTokenize)(Fts5Tokenizer*, 12867 void *pCtx, 12868 int flags, /* Mask of FTS5_TOKENIZE_* flags */ 12869 const char *pText, int nText, 12870 int (*xToken)( 12871 void *pCtx, /* Copy of 2nd argument to xTokenize() */ 12872 int tflags, /* Mask of FTS5_TOKEN_* flags */ 12873 const char *pToken, /* Pointer to buffer containing token */ 12874 int nToken, /* Size of token in bytes */ 12875 int iStart, /* Byte offset of token within input text */ 12876 int iEnd /* Byte offset of end of token within input text */ 12877 ) 12878 ); 12879}; 12880 12881/* Flags that may be passed as the third argument to xTokenize() */ 12882#define FTS5_TOKENIZE_QUERY 0x0001 12883#define FTS5_TOKENIZE_PREFIX 0x0002 12884#define FTS5_TOKENIZE_DOCUMENT 0x0004 12885#define FTS5_TOKENIZE_AUX 0x0008 12886 12887/* Flags that may be passed by the tokenizer implementation back to FTS5 12888** as the third argument to the supplied xToken callback. */ 12889#define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */ 12890 12891/* 12892** END OF CUSTOM TOKENIZERS 12893*************************************************************************/ 12894 12895/************************************************************************* 12896** FTS5 EXTENSION REGISTRATION API 12897*/ 12898typedef struct fts5_api fts5_api; 12899struct fts5_api { 12900 int iVersion; /* Currently always set to 2 */ 12901 12902 /* Create a new tokenizer */ 12903 int (*xCreateTokenizer)( 12904 fts5_api *pApi, 12905 const char *zName, 12906 void *pContext, 12907 fts5_tokenizer *pTokenizer, 12908 void (*xDestroy)(void*) 12909 ); 12910 12911 /* Find an existing tokenizer */ 12912 int (*xFindTokenizer)( 12913 fts5_api *pApi, 12914 const char *zName, 12915 void **ppContext, 12916 fts5_tokenizer *pTokenizer 12917 ); 12918 12919 /* Create a new auxiliary function */ 12920 int (*xCreateFunction)( 12921 fts5_api *pApi, 12922 const char *zName, 12923 void *pContext, 12924 fts5_extension_function xFunction, 12925 void (*xDestroy)(void*) 12926 ); 12927}; 12928 12929/* 12930** END OF REGISTRATION API 12931*************************************************************************/ 12932 12933#ifdef __cplusplus 12934} /* end of the 'extern "C"' block */ 12935#endif 12936 12937#endif /* _FTS5_H */ 12938 12939/******** End of fts5.h *********/ 12940