@ohos.data.dataAbility (DataAbility Predicates)

DataAbility provides APIs for creating predicates, which implement different query methods for relational database (RDB) stores.

NOTE

The initial APIs of this module are supported since API version 7. Newly added APIs will be marked with a superscript to indicate their earliest API version.

Modules to Import

import dataAbility from '@ohos.data.dataAbility';

dataAbility.createRdbPredicates

createRdbPredicates(name: string, dataAbilityPredicates: DataAbilityPredicates): rdb.RdbPredicates

Creates an RdbPredicates object from a DataAbilityPredicates object.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Parameters

Return value

Example

  let dataAbilityPredicates = new dataAbility.DataAbilityPredicates()
  dataAbilityPredicates.equalTo("NAME", "Rose")
  let predicates = dataAbility.createRdbPredicates("EMPLOYEE", dataAbilityPredicates)

DataAbilityPredicates

Provides predicates for implementing diverse query methods.

equalTo

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

Sets a DataAbilityPredicates object to match the field with data type ValueType and value equal to the specified value.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Parameters

Return value

Example

  dataAbilityPredicates.equalTo("NAME", "lisi")

notEqualTo

notEqualTo(field: string, value: ValueType): DataAbilityPredicates

Sets a DataAbilityPredicates object to match the field with data type ValueType and value not equal to the specified value.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Parameters

Return value

Example

  dataAbilityPredicates.notEqualTo("NAME", "lisi")

beginWrap

beginWrap(): DataAbilityPredicates

Adds a left parenthesis to this DataAbilityPredicates.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Return value

Example

  dataAbilityPredicates.equalTo("NAME", "lisi")
      .beginWrap()
      .equalTo("AGE", 18)
      .or()
      .equalTo("SALARY", 200.5)
      .endWrap()

endWrap

endWrap(): DataAbilityPredicates

Adds a right parenthesis to this DataAbilityPredicates.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Return value

Example

  dataAbilityPredicates.equalTo("NAME", "lisi")
      .beginWrap()
      .equalTo("AGE", 18)
      .or()
      .equalTo("SALARY", 200.5)
      .endWrap()

or

or(): DataAbilityPredicates

Adds the OR condition to this DataAbilityPredicates.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Return value

Example

  dataAbilityPredicates.equalTo("NAME", "Lisa")
      .or()
      .equalTo("NAME", "Rose")

and

and(): DataAbilityPredicates

Adds the AND condition to this DataAbilityPredicates.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Return value

Example

  dataAbilityPredicates.equalTo("NAME", "Lisa")
      .and()
      .equalTo("SALARY", 200.5)

contains

contains(field: string, value: string): DataAbilityPredicates

Sets a DataAbilityPredicates object to match a string containing the specified value.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Parameters

Return value

Example

  dataAbilityPredicates.contains("NAME", "os")

beginsWith

beginsWith(field: string, value: string): DataAbilityPredicates

Sets a DataAbilityPredicates object to match a string that starts with the specified value.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Parameters

Return value

Example

  dataAbilityPredicates.beginsWith("NAME", "os")

endsWith

endsWith(field: string, value: string): DataAbilityPredicates

Sets a DataAbilityPredicates object to match a string that ends with the specified value.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Parameters

Return value

Example

  dataAbilityPredicates.endsWith("NAME", "se")

isNull

isNull(field: string): DataAbilityPredicates

Sets a DataAbilityPredicates object to match the field whose value is null.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Parameters

Return value

Example

  dataAbilityPredicates.isNull("NAME")

isNotNull

isNotNull(field: string): DataAbilityPredicates

Sets a DataAbilityPredicates object to match the field whose value is not null.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Parameters

Return value

Example

  dataAbilityPredicates.isNotNull("NAME")

like

like(field: string, value: string): DataAbilityPredicates

Sets a DataAbilityPredicates object to match a string that is similar to the specified value.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Parameters

Return value

Example

  dataAbilityPredicates.like("NAME", "%os%")

glob

glob(field: string, value: string): DataAbilityPredicates

Sets a DataAbilityPredicates object to match the specified string.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Parameters

Return value

Example

  dataAbilityPredicates.glob("NAME", "?h*g")

between

between(field: string, low: ValueType, high: ValueType): DataAbilityPredicates

Sets a DataAbilityPredicates object to match a field whose data type is ValueType and value is within the specified range.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Parameters

Return value

Example

  dataAbilityPredicates.between("AGE", 10, 50)

notBetween

notBetween(field: string, low: ValueType, high: ValueType): DataAbilityPredicates

Sets a DataAbilityPredicates object to match the field with data type ValueType and value out of the specified range.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Parameters

Return value

Example

  dataAbilityPredicates.notBetween("AGE", 10, 50)

greaterThan

greaterThan(field: string, value: ValueType): DataAbilityPredicates

Sets a DataAbilityPredicates object to match the field with data type ValueType and value greater than the specified value.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Parameters

Return value

Example

  dataAbilityPredicates.greaterThan("AGE", 18)

lessThan

lessThan(field: string, value: ValueType): DataAbilityPredicates

Sets a DataAbilityPredicates object to match the field with data type ValueType and value less than the specified value.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Parameters

Return value

Example

  dataAbilityPredicates.lessThan("AGE", 20)

greaterThanOrEqualTo

greaterThanOrEqualTo(field: string, value: ValueType): DataAbilityPredicates

Sets a DataAbilityPredicates object to match the field with data type ValueType and value greater than or equal to the specified value.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Parameters

Return value

Example

  dataAbilityPredicates.greaterThanOrEqualTo("AGE", 18)

lessThanOrEqualTo

lessThanOrEqualTo(field: string, value: ValueType): DataAbilityPredicates

Sets a DataAbilityPredicates object to match the field with data type ValueType and value less than or equal to the specified value.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Parameters

Return value

Example

  dataAbilityPredicates.lessThanOrEqualTo("AGE", 20)

orderByAsc

orderByAsc(field: string): DataAbilityPredicates

Sets a DataAbilityPredicates object to match the column with values sorted in ascending order.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Parameters

Return value

Example

  dataAbilityPredicates.orderByAsc("NAME")

orderByDesc

orderByDesc(field: string): DataAbilityPredicates

Sets a DataAbilityPredicates object to match the column with values sorted in descending order.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Parameters

Return value

Example

  dataAbilityPredicates.orderByDesc("AGE")

distinct

distinct(): DataAbilityPredicates

Sets a DataAbilityPredicates object to filter out duplicate records.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Return value

Example

  dataAbilityPredicates.equalTo("NAME", "Rose").distinct()

limitAs

limitAs(value: number): DataAbilityPredicates

Set a DataAbilityPredicates object to specify the maximum number of records.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Parameters

Return value

Example

  dataAbilityPredicates.equalTo("NAME", "Rose").limitAs(3)

offsetAs

offsetAs(rowOffset: number): DataAbilityPredicates

Sets a DataAbilityPredicates object to specify the start position of the returned result.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Parameters

Return value

Example

  dataAbilityPredicates.equalTo("NAME", "Rose").offsetAs(3)

groupBy

groupBy(fields: Array<string>): DataAbilityPredicates

Sets a DataAbilityPredicates object to group rows that have the same value into summary rows.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Parameters

Return value

Example

  dataAbilityPredicates.groupBy(["AGE", "NAME"])

indexedBy

indexedBy(field: string): DataAbilityPredicates

Sets a DataAbilityPredicates object to specify the index column.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Parameters

Return value

Example

  dataAbilityPredicates.indexedBy("SALARY_INDEX")

in

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

Sets a DataAbilityPredicates object to match the field with data type Array<ValueType> and value within the specified range.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Parameters

Return value

Example

  dataAbilityPredicates.in("AGE", [18, 20])

notIn

notIn(field: string, value: Array&lt;ValueType&gt;): DataAbilityPredicates

Sets a DataAbilityPredicates object to match the field with data type Array<ValueType> and value out of the specified range.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

Parameters

Return value

Example

  dataAbilityPredicates.notIn("NAME", ["Lisa", "Rose"])

ValueType

Enumerates the value types.

System capability: SystemCapability.DistributedDataManager.DataShare.Core

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