@ohos.data.dataSharePredicates (DataShare Predicates)

DataSharePredicates provides a filter object to query data in a database by using DataShare APIs. It is often used to update, delete, and query data.

The APIs provided by DataSharePredicates correspond to the filter criteria of the database. Before using the APIs, you need to have basic database knowledge.

NOTE

• The initial APIs of this module are supported since API version 9. Newly added APIs will be marked with a superscript to indicate their earliest API version.

• The APIs of this module can be used only in the stage model.

Modules to Import

import { dataSharePredicates } from '@kit.ArkData';

DataSharePredicates

Provides APIs for setting different DataSharePredicates objects. This type is not multi-thread safe. If a DataSharePredicates instance is operated by multiple threads at the same time in an application, use a lock for it.

equalTo¹⁰⁺

equalTo(field: string, value: ValueType): DataSharePredicates

Creates a DataSharePredicates object to search for the records in the specified column that are equal to the given value.

Currently, only the relational database (RDB) and key-value database (KVDB, schema) support this DataSharePredicates object.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Parameters

Return value

Example

let predicates = new dataSharePredicates.DataSharePredicates()
predicates.equalTo("NAME", "Rose")

and¹⁰⁺

and(): DataSharePredicates

Creates a DataSharePredicates object to add the AND condition.

Currently, only the RDB and KVDB (schema) support this DataSharePredicates object.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Return value

Example

let predicates = new dataSharePredicates.DataSharePredicates()
predicates.equalTo("NAME", "lisi")
    .and()
    .equalTo("SALARY", 200.5)

orderByAsc¹⁰⁺

orderByAsc(field: string): DataSharePredicates

Creates a DataSharePredicates object that sorts records in ascending order.

Currently, only the RDB and KVDB (schema) support this DataSharePredicates object.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Parameters

Return value

Example

let predicates = new dataSharePredicates.DataSharePredicates()
predicates.orderByAsc("AGE")

orderByDesc¹⁰⁺

orderByDesc(field: string): DataSharePredicates

Creates a DataSharePredicates object that sorts data in descending order.

Currently, only the RDB and KVDB (schema) support this DataSharePredicates object.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Parameters

Return value

Example

let predicates = new dataSharePredicates.DataSharePredicates()
predicates.orderByDesc("AGE")

limit¹⁰⁺

limit(total: number, offset: number): DataSharePredicates

Creates a DataSharePredicates object to specify the number of records in the result and the start position.

Currently, only the RDB and KVDB (schema) support this DataSharePredicates object.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Parameters

Return value

Example

let predicates = new dataSharePredicates.DataSharePredicates()
predicates.equalTo("NAME", "Rose").limit(10, 3)

in¹⁰⁺

in(field: string, value: Array<ValueType>): DataSharePredicates

Creates a DataSharePredicates object to search for the records in the specified column that are within the specified range.

Currently, only the RDB and KVDB (schema) support this DataSharePredicates object.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Parameters

Return value

Example

let predicates = new dataSharePredicates.DataSharePredicates()
predicates.in("AGE", [18, 20])

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