1e41f4b71Sopenharmony_ci# OH_Predicates
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4e41f4b71Sopenharmony_ci## Overview
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6e41f4b71Sopenharmony_ciDefines the predicates for RDB stores.
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8e41f4b71Sopenharmony_ci**Since**: 10
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10e41f4b71Sopenharmony_ci**Related module**: [RDB](_r_d_b.md)
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13e41f4b71Sopenharmony_ci## Summary
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16e41f4b71Sopenharmony_ci### Member Variables
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18e41f4b71Sopenharmony_ci| Name| Description|
19e41f4b71Sopenharmony_ci| -------- | -------- |
20e41f4b71Sopenharmony_ci| [id](_r_d_b.md#id-25) | Unique identifier of the **OH_Predicates** struct.|
21e41f4b71Sopenharmony_ci| [equalTo](_r_d_b.md#equalto) | Pointer to the function used to set a predicates object to match the field whose value is equal to the specified value.|
22e41f4b71Sopenharmony_ci| [notEqualTo](_r_d_b.md#notequalto) | Pointer to the function used to set a predicates object to match the field whose value is not equal to the specified value.|
23e41f4b71Sopenharmony_ci| [beginWrap](_r_d_b.md#beginwrap) | Pointer to the function used to add a left parenthesis to the predicates.|
24e41f4b71Sopenharmony_ci| [endWrap](_r_d_b.md#endwrap) | Pointer to the function used to add a right parenthesis to the predicates.|
25e41f4b71Sopenharmony_ci| [orOperate](_r_d_b.md#oroperate) | Pointer to the function used to add the OR operator to the predicates.|
26e41f4b71Sopenharmony_ci| [andOperate](_r_d_b.md#andoperate) | Pointer to the function used to add the AND operator to the predicates.|
27e41f4b71Sopenharmony_ci| [isNull](_r_d_b.md#isnull-22) | Pointer to the function used to set a predicates object to match the field whose value is null.|
28e41f4b71Sopenharmony_ci| [isNotNull](_r_d_b.md#isnotnull) | Pointer to the function used to set a predicates object to match the field whose value is not null.|
29e41f4b71Sopenharmony_ci| [like](_r_d_b.md#like) | Pointer to the function used to set a predicates object to match a string that is similar to the specified value.|
30e41f4b71Sopenharmony_ci| [between](_r_d_b.md#between) | Pointer to the function used to set a predicates object to match the field whose value is within the specified range.|
31e41f4b71Sopenharmony_ci| [notBetween](_r_d_b.md#notbetween) | Pointer to the function used to set a predicates object to match the field whose value is out of the specified range.|
32e41f4b71Sopenharmony_ci| [greaterThan](_r_d_b.md#greaterthan) | Pointer to the function used to set a predicates object to match the field with value greater than the specified value.|
33e41f4b71Sopenharmony_ci| [lessThan](_r_d_b.md#lessthan) | Pointer to the function used to set a predicates object to match the field with value less than the specified value.|
34e41f4b71Sopenharmony_ci| [greaterThanOrEqualTo](_r_d_b.md#greaterthanorequalto) | Pointer to the function used to set a predicates object to match the field with value greater than or equal to the specified value.|
35e41f4b71Sopenharmony_ci| [lessThanOrEqualTo](_r_d_b.md#lessthanorequalto) | Pointer to the function used to set a predicates object to match the field with value less than or equal to the specified value.|
36e41f4b71Sopenharmony_ci| [orderBy](_r_d_b.md#orderby) | Pointer to the function used to set a predicates object to sort the values in a column in ascending or descending order.|
37e41f4b71Sopenharmony_ci| [distinct](_r_d_b.md#distinct) | Pointer to the function used to set a predicates object to filter out duplicate records.|
38e41f4b71Sopenharmony_ci| [limit](_r_d_b.md#limit) | Pointer to the function used to set a predicates object to specify the maximum number of records.|
39e41f4b71Sopenharmony_ci| [offset](_r_d_b.md#offset) | Pointer to the function used to set a predicates object to specify the start position of the returned result.|
40e41f4b71Sopenharmony_ci| [groupBy](_r_d_b.md#groupby) | Pointer to the function used to set a predicates object to group rows that have the same value into summary rows.|
41e41f4b71Sopenharmony_ci| [in](_r_d_b.md#in) | Pointer to the function used to set a predicates object to match the field with the value within the specified range.|
42e41f4b71Sopenharmony_ci| [notIn](_r_d_b.md#notin) | Pointer to the function used to set a predicates object to match the field with the value out of the specified range.|
43e41f4b71Sopenharmony_ci| [clear](_r_d_b.md#clear-12) | Pointer to the function used to clear a predicates instance.|
44e41f4b71Sopenharmony_ci| [destroy](_r_d_b.md#destroy-24) | Destroys an **OH_Predicates** object and reclaims the memory occupied.|
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