@ohos.data.distributedKVStore (Distributed KV Store)

The distributedKVStore module implements collaboration between databases for different devices that forms a Super Device. You can use the APIs provided by this module to save application data to a distributed key-value (KV) store and perform operations, such as adding, deleting, modifying, querying, and synchronizing data in distributed KV stores.

The distributedKVStore module provides the following functions:

• KVManager: provides a KVManager instance to obtain KV store information.
• KVStoreResultSet: provides APIs for accessing the results obtained from a KV store.
• Query: provides APIs for setting predicates for data query.
• SingleKVStore: provides APIs for querying and synchronizing data in single KV stores. The single KV stores manage data without distinguishing devices.
• DeviceKVStore: provides APIs for querying and synchronizing data in device KV stores. This class inherits from SingleKVStore. The device KV stores manage data by device.

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.

Modules to Import

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

KVManagerConfig

Provides the KVManager instance configuration, including the bundle name of the invoker and the application context.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Constants

Provides constants of the distributed KV store.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

ValueType

Enumerates the types of the value in a KV pair.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Value

Defines the value object in a KV store.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Entry

Defines the KV pairs stored in a KV store.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

ChangeNotification

Defines the content of a data change notification, including inserted data, updated data, deleted data, and device ID.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

SyncMode

Enumerates the synchronization modes.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

SubscribeType

Enumerates the subscription types.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

KVStoreType

Enumerates the distributed KV store types.

SecurityLevel

Enumerates the KV store security levels.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Options

Provides KV store configuration.

Schema

Defines the schema of a KV store. You can create a Schema object and place it in Options when creating or opening a KV store.

System capability: SystemCapability.DistributedDataManager.KVStore.DistributedKVStore

constructor

constructor()

A constructor used to create a Schema instance.

System capability: SystemCapability.DistributedDataManager.KVStore.DistributedKVStore

FieldNode

Represents a Schema instance, which provides the methods for defining the values stored in a KV store.

System capability: SystemCapability.DistributedDataManager.KVStore.DistributedKVStore

constructor

constructor(name: string)

A constructor used to create a FieldNode instance with a string field.

System capability: SystemCapability.DistributedDataManager.KVStore.DistributedKVStore

Parameters

appendChild

appendChild(child: FieldNode): boolean

Appends a child node to this FieldNode.

System capability: SystemCapability.DistributedDataManager.KVStore.DistributedKVStore

Parameters

Return value

Example

try {
  let node: distributedKVStore.FieldNode | null = new distributedKVStore.FieldNode("root");
  let child1: distributedKVStore.FieldNode | null = new distributedKVStore.FieldNode("child1");
  let child2: distributedKVStore.FieldNode | null = new distributedKVStore.FieldNode("child2");
  let child3: distributedKVStore.FieldNode | null = new distributedKVStore.FieldNode("child3");
  node.appendChild(child1);
  node.appendChild(child2);
  node.appendChild(child3);
  console.info("appendNode " + JSON.stringify(node));
  child1 = null;
  child2 = null;
  child3 = null;
  node = null;
} catch (e) {
  console.error("AppendChild " + e);
}

distributedKVStore.createKVManager

createKVManager(config: KVManagerConfig): KVManager

Creates a KVManager instance for KV store management.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

Stage model:

import UIAbility from '@ohos.app.ability.UIAbility';
import { BusinessError } from '@ohos.base';

let kvManager: distributedKVStore.KVManager;

export default class EntryAbility extends UIAbility {
  onCreate() {
    console.info("MyAbilityStage onCreate")
    let context = this.context
    const kvManagerConfig: distributedKVStore.KVManagerConfig = {
      context: context,
      bundleName: 'com.example.datamanagertest',
    }
    try {
      kvManager = distributedKVStore.createKVManager(kvManagerConfig);
      console.info("Succeeded in creating KVManager");
    } catch (e) {
      let error = e as BusinessError;
      console.error(`Failed to create KVManager.code is ${error.code},message is ${error.message}`);
    }
  }
}

FA model:

import featureAbility from '@ohos.ability.featureAbility';
import { BusinessError } from '@ohos.base';

let kvManager: distributedKVStore.KVManager;
let context = featureAbility.getContext()
const kvManagerConfig: distributedKVStore.KVManagerConfig = {
  context: context,
  bundleName: 'com.example.datamanagertest',
}
try {
  kvManager = distributedKVStore.createKVManager(kvManagerConfig);
  console.info("Succeeded in creating KVManager");
} catch (e) {
  let error = e as BusinessError;
  console.error(`Failed to create KVManager.code is ${error.code},message is ${error.message}`);
}

KVManager

Provides an instance to obtain information about a distributed KV store. Before calling any API in KVManager, you must use createKVManager to create a KVManager instance.

getKVStore

getKVStore<T>(storeId: string, options: Options, callback: AsyncCallback<T>): void

Creates and obtains a distributed KV store. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

Example

import { BusinessError } from '@ohos.base';

let kvStore: distributedKVStore.SingleKVStore | null;
try {
  const options: distributedKVStore.Options = {
    createIfMissing: true,
    encrypt: false,
    backup: false,
    autoSync: true,
    kvStoreType: distributedKVStore.KVStoreType.SINGLE_VERSION,
    securityLevel: distributedKVStore.SecurityLevel.S2,
  };
  kvManager.getKVStore('storeId', options, (err, store: distributedKVStore.SingleKVStore) => {
    if (err) {
      console.error(`Failed to get KVStore.code is ${err.code},message is ${err.message}`);
      return;
    }
    console.info("Succeeded in getting KVStore");
    kvStore = store;
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`An unexpected error occurred.code is ${error.code},message is ${error.message}`);
}

getKVStore

getKVStore<T>(storeId: string, options: Options): Promise<T>

Creates and obtains a distributed KV store. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

Example

import { BusinessError } from '@ohos.base';

let kvStore: distributedKVStore.SingleKVStore | null;
try {
  const options: distributedKVStore.Options = {
    createIfMissing: true,
    encrypt: false,
    backup: false,
    autoSync: true,
    kvStoreType: distributedKVStore.KVStoreType.SINGLE_VERSION,
    securityLevel: distributedKVStore.SecurityLevel.S2,
  };
  kvManager.getKVStore<distributedKVStore.SingleKVStore>('storeId', options).then((store: distributedKVStore.SingleKVStore) => {
    console.info("Succeeded in getting KVStore");
    kvStore = store;
  }).catch((err: BusinessError) => {
    console.error(`Failed to get KVStore.code is ${err.code},message is ${err.message}`);
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`An unexpected error occurred.code is ${error.code},message is ${error.message}`);
}

closeKVStore

closeKVStore(appId: string, storeId: string, callback: AsyncCallback<void>): void

Closes a distributed KV store. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Example

import { BusinessError } from '@ohos.base';

let kvStore: distributedKVStore.SingleKVStore | null;
const options: distributedKVStore.Options = {
  createIfMissing: true,
  encrypt: false,
  backup: false,
  autoSync: true,
  kvStoreType: distributedKVStore.KVStoreType.SINGLE_VERSION,
  schema: undefined,
  securityLevel: distributedKVStore.SecurityLevel.S2,
}
try {
  kvManager.getKVStore('storeId', options, async (err, store: distributedKVStore.SingleKVStore | null) => {
    if (err != undefined) {
      console.error(`Failed to get KVStore.code is ${err.code},message is ${err.message}`);
      return;
    }
    console.info('Succeeded in getting KVStore');
    kvStore = store;
    kvStore = null;
    store = null;
    kvManager.closeKVStore('appId', 'storeId', (err)=> {
      if (err != undefined) {
        console.error(`Failed to close KVStore.code is ${err.code},message is ${err.message}`);
        return;
      }
      console.info('Succeeded in closing KVStore');
    });
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`An unexpected error occurred.code is ${error.code},message is ${error.message}`);
}

closeKVStore

closeKVStore(appId: string, storeId: string): Promise<void>

Closes a distributed KV store. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

import { BusinessError } from '@ohos.base';

let kvStore: distributedKVStore.SingleKVStore | null;

const options: distributedKVStore.Options = {
  createIfMissing: true,
  encrypt: false,
  backup: false,
  autoSync: true,
  kvStoreType: distributedKVStore.KVStoreType.SINGLE_VERSION,
  schema: undefined,
  securityLevel: distributedKVStore.SecurityLevel.S2,
}
try {
  kvManager.getKVStore<distributedKVStore.SingleKVStore>('storeId', options).then(async (store: distributedKVStore.SingleKVStore | null) => {
    console.info('Succeeded in getting KVStore');
    kvStore = store;
    kvStore = null;
    store = null;
    kvManager.closeKVStore('appId', 'storeId').then(() => {
      console.info('Succeeded in closing KVStore');
    }).catch((err: BusinessError) => {
      console.error(`Failed to close KVStore.code is ${err.code},message is ${err.message}`);
    });
  }).catch((err: BusinessError) => {
    console.error(`Failed to get KVStore.code is ${err.code},message is ${err.message}`);
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`Failed to close KVStore.code is ${error.code},message is ${error.message}`);
}

deleteKVStore

deleteKVStore(appId: string, storeId: string, callback: AsyncCallback<void>): void

Deletes a distributed KV store. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

Example

import { BusinessError } from '@ohos.base';

let kvStore: distributedKVStore.SingleKVStore | null;

const options: distributedKVStore.Options = {
  createIfMissing: true,
  encrypt: false,
  backup: false,
  autoSync: true,
  kvStoreType: distributedKVStore.KVStoreType.SINGLE_VERSION,
  schema: undefined,
  securityLevel: distributedKVStore.SecurityLevel.S2,
}
try {
  kvManager.getKVStore('store', options, async (err, store: distributedKVStore.SingleKVStore | null) => {
    if (err != undefined) {
      console.error(`Failed to get KVStore.code is ${err.code},message is ${err.message}`);
      return;
    }
    console.info('Succeeded in getting KVStore');
    kvStore = store;
    kvStore = null;
    store = null;
    kvManager.deleteKVStore('appId', 'storeId', (err) => {
      if (err != undefined) {
        console.error(`Failed to delete KVStore.code is ${err.code},message is ${err.message}`);
        return;
      }
      console.info(`Succeeded in deleting KVStore`);
    });
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`Failed to delete KVStore.code is ${error.code},message is ${error.message}`);
}

deleteKVStore

deleteKVStore(appId: string, storeId: string): Promise<void>

Deletes a distributed KV store. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

Example

import { BusinessError } from '@ohos.base';

let kvStore: distributedKVStore.SingleKVStore | null;

const options: distributedKVStore.Options = {
  createIfMissing: true,
  encrypt: false,
  backup: false,
  autoSync: true,
  kvStoreType: distributedKVStore.KVStoreType.SINGLE_VERSION,
  schema: undefined,
  securityLevel: distributedKVStore.SecurityLevel.S2,
}
try {
  kvManager.getKVStore<distributedKVStore.SingleKVStore>('storeId', options).then(async (store: distributedKVStore.SingleKVStore | null) => {
    console.info('Succeeded in getting KVStore');
    kvStore = store;
    kvStore = null;
    store = null;
    kvManager.deleteKVStore('appId', 'storeId').then(() => {
      console.info('Succeeded in deleting KVStore');
    }).catch((err: BusinessError) => {
      console.error(`Failed to delete KVStore.code is ${err.code},message is ${err.message}`);
    });
  }).catch((err: BusinessError) => {
    console.error(`Failed to get KVStore.code is ${err.code},message is ${err.message}`);
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`Failed to delete KVStore.code is ${error.code},message is ${error.message}`);
}

getAllKVStoreId

getAllKVStoreId(appId: string, callback: AsyncCallback<string[]>): void

Obtains the IDs of all distributed KV stores that are created by getKVStore and have not been deleted by deleteKVStore. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Example

import { BusinessError } from '@ohos.base';

try {
  kvManager.getAllKVStoreId('appId', (err, data) => {
    if (err != undefined) {
      console.error(`Failed to get AllKVStoreId.code is ${err.code},message is ${err.message}`);
      return;
    }
    console.info('Succeeded in getting AllKVStoreId');
    console.info(`GetAllKVStoreId size = ${data.length}`);
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`Failed to get AllKVStoreId.code is ${error.code},message is ${error.message}`);
}

getAllKVStoreId

getAllKVStoreId(appId: string): Promise<string[]>

Obtains the IDs of all distributed KV stores that are created by getKVStore and have not been deleted by deleteKVStore. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

import { BusinessError } from '@ohos.base';

try {
  console.info('GetAllKVStoreId');
  kvManager.getAllKVStoreId('appId').then((data: string[]) => {
    console.info('Succeeded in getting AllKVStoreId');
    console.info(`GetAllKVStoreId size = ${data.length}`);
  }).catch((err: BusinessError) => {
    console.error(`Failed to get AllKVStoreId.code is ${err.code},message is ${err.message}`);
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`Failed to get AllKVStoreId.code is ${error.code},message is ${error.message}`);
}

on('distributedDataServiceDie')

on(event: 'distributedDataServiceDie', deathCallback: Callback<void>): void

Subscribes to service status changes. If the service is terminated, you need to register the callbacks for data change notifications and synchronization complete notifications again. In addition, an error will be returned for a synchronization operation.

System capability: SystemCapability.DistributedDataManager.KVStore.DistributedKVStore

Parameters

Example

import { BusinessError } from '@ohos.base';

try {
  console.info('KVManagerOn');
  const deathCallback = () => {
    console.info('death callback call');
  }
  kvManager.on('distributedDataServiceDie', deathCallback);
} catch (e) {
  let error = e as BusinessError;
  console.error(`An unexpected error occurred.code is ${error.code},message is ${error.message}`);
}

off('distributedDataServiceDie')

off(event: 'distributedDataServiceDie', deathCallback?: Callback<void>): void

Unsubscribes from service status changes. The deathCallback parameter must be a callback registered for subscribing to service status changes. Otherwise, the unsubscription will fail.

System capability: SystemCapability.DistributedDataManager.KVStore.DistributedKVStore

Parameters

Example

import { BusinessError } from '@ohos.base';

try {
  console.info('KVManagerOff');
  const deathCallback = () => {
    console.info('death callback call');
  }
  kvManager.off('distributedDataServiceDie', deathCallback);
} catch (e) {
  let error = e as BusinessError;
  console.error(`An unexpected error occurred.code is ${error.code},message is ${error.message}`);
}

KVStoreResultSet

Provides APIs for obtaining the distributed KV store result sets. A maximum of eight result sets can be opened at a time.

Before calling any API in KVStoreResultSet, you must use getKVStore to construct a SingleKVStore or DeviceKVStore instance.

getCount

getCount(): number

Obtains the total number of rows in the result set.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

import { BusinessError } from '@ohos.base';

try {
  let resultSet: distributedKVStore.KVStoreResultSet;
  let count: number;
  kvStore.getResultSet('batch_test_string_key').then((result) => {
    console.info('getResultSet succeed.');
    resultSet = result;
    count = resultSet.getCount();
    console.info("getCount succeed:" + count);
  }).catch((err: BusinessError) => {
    console.error('getResultSet failed: ' + err);
  });
} catch (e) {
  console.error("getCount failed: " + e);
}

getPosition

getPosition(): number

Obtains the current data read position (position from which data is read) in the result set. The read position changes with the operations, such as moveToFirst and moveToLast.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

import { BusinessError } from '@ohos.base';

try {
  let resultSet: distributedKVStore.KVStoreResultSet;
  let position: number;
  kvStore.getResultSet('batch_test_string_key').then((result) => {
    console.info('getResultSet succeeded.');
    resultSet = result;
    position = resultSet.getPosition();
    console.info("getPosition succeed:" + position);
  }).catch((err: BusinessError) => {
    console.error('getResultSet failed: ' + err);
  });
} catch (e) {
  console.error("getPosition failed: " + e);
}

moveToFirst

moveToFirst(): boolean

Moves the data read position to the first row. If the result set is empty, false will be returned.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

import { BusinessError } from '@ohos.base';

try {
  let resultSet: distributedKVStore.KVStoreResultSet;
  let moved: boolean;
  kvStore.getResultSet('batch_test_string_key').then((result) => {
    console.info('getResultSet succeed.');
    resultSet = result;
    moved = resultSet.moveToFirst();
    console.info("moveToFirst succeed: " + moved);
  }).catch((err: BusinessError) => {
    console.error('getResultSet failed: ' + err);
  });
} catch (e) {
  console.error("moveToFirst failed " + e);
}

moveToLast

moveToLast(): boolean

Moves the data read position to the last row. If the result set is empty, false will be returned.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

import { BusinessError } from '@ohos.base';

try {
  let resultSet: distributedKVStore.KVStoreResultSet;
  let moved: boolean;
  kvStore.getResultSet('batch_test_string_key').then((result) => {
    console.info('getResultSet succeed.');
    resultSet = result;
    moved = resultSet.moveToLast();
    console.info("moveToLast succeed:" + moved);
  }).catch((err: BusinessError) => {
    console.error('getResultSet failed: ' + err);
  });
} catch (e) {
  console.error("moveToLast failed: " + e);
}

moveToNext

moveToNext(): boolean

Moves the data read position to the next row. If the result set is empty, false will be returned. This API applies when the whole result set is obtained.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

import { BusinessError } from '@ohos.base';

try {
  let resultSet: distributedKVStore.KVStoreResultSet;
  let moved: boolean;
  kvStore.getResultSet('batch_test_string_key').then((result) => {
    console.info('getResultSet succeed.');
    resultSet = result;
    do {
      moved = resultSet.moveToNext();
      console.info("moveToNext succeed: " + moved);
    } while (moved)
  }).catch((err: BusinessError) => {
    console.error('getResultSet failed: ' + err);
  });
} catch (e) {
  console.error("moveToNext failed: " + e);
}

moveToPrevious

moveToPrevious(): boolean

Moves the data read position to the previous row. If the result set is empty, false will be returned. This API applies when the whole result set is obtained.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

import { BusinessError } from '@ohos.base';

try {
  let resultSet: distributedKVStore.KVStoreResultSet;
  let moved: boolean;
  kvStore.getResultSet('batch_test_string_key').then((result) => {
    console.info('getResultSet succeed.');
    resultSet = result;
    moved = resultSet.moveToLast();
    moved = resultSet.moveToPrevious();
    console.info("moveToPrevious succeed:" + moved);
  }).catch((err: BusinessError) => {
    console.error('getResultSet failed: ' + err);
  });
} catch (e) {
  console.error("moveToPrevious failed: " + e);
}

move

move(offset: number): boolean

Moves the data read position with the specified offset from the current position. That is, moves the number of rows specified by offset from the current position.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

import { BusinessError } from '@ohos.base';

try {
  let resultSet: distributedKVStore.KVStoreResultSet;
  let moved: boolean;
  kvStore.getResultSet('batch_test_string_key').then((result) => {
    console.info('Succeeded in getting resultSet');
    resultSet = result;
    moved = resultSet.move(2); // If the current position is 0, move the read position forward by two rows, that is, move to row 3.
    console.info(`Succeeded in moving.moved = ${moved}`);
  }).catch((err: BusinessError) => {
    console.error(`Failed to get resultSet.code is ${err.code},message is ${err.message}`);
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`Failed to move.code is ${error.code},message is ${error.message}`);
}

moveToPosition

moveToPosition(position: number): boolean

Moves the data read position from 0 to an absolute position.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

import { BusinessError } from '@ohos.base';

try {
  let resultSet: distributedKVStore.KVStoreResultSet;
  let moved: boolean;
  kvStore.getResultSet('batch_test_string_key').then((result) => {
    console.info('Succeeded in getting resultSet');
    resultSet = result;
    moved = resultSet.moveToPosition(1);
    console.info(`Succeeded in moving to position.moved=${moved}`);
  }).catch((err: BusinessError) => {
    console.error(`Failed to get resultSet.code is ${err.code},message is ${err.message}`);
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`Failed to move to position.code is ${error.code},message is ${error.message}`);
}

isFirst

isFirst(): boolean

Checks whether the data read position is the first row.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

import { BusinessError } from '@ohos.base';

try {
  let resultSet: distributedKVStore.KVStoreResultSet;
  let isfirst: boolean;
  kvStore.getResultSet('batch_test_string_key').then((result) => {
    console.info('getResultSet succeed.');
    resultSet = result;
    isfirst = resultSet.isFirst();
    console.info("Check isFirst succeed:" + isfirst);
  }).catch((err: BusinessError) => {
    console.error('getResultSet failed: ' + err);
  });
} catch (e) {
  console.error("Check isFirst failed: " + e);
}

isLast

isLast(): boolean

Checks whether the data read position is the last row.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

import { BusinessError } from '@ohos.base';

try {
  let resultSet: distributedKVStore.KVStoreResultSet;
  let islast: boolean;
  kvStore.getResultSet('batch_test_string_key').then((result) => {
    console.info('getResultSet succeed.');
    resultSet = result;
    islast = resultSet.isLast();
    console.info("Check isLast succeed: " + islast);
  }).catch((err: BusinessError) => {
    console.error('getResultSet failed: ' + err);
  });
} catch (e) {
  console.error("Check isLast failed: " + e);
}

isBeforeFirst

isBeforeFirst(): boolean

Checks whether the data read position is before the first row.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

import { BusinessError } from '@ohos.base';

try {
  let resultSet: distributedKVStore.KVStoreResultSet;
  kvStore.getResultSet('batch_test_string_key').then((result) => {
    console.info('getResultSet succeed.');
    resultSet = result;
    let isbeforefirst = resultSet.isBeforeFirst();
    console.info("Check isBeforeFirst succeed: " + isbeforefirst);
  }).catch((err: BusinessError) => {
    console.error('getResultSet failed: ' + err);
  });
} catch (e) {
  console.error("Check isBeforeFirst failed: " + e);
}

isAfterLast

isAfterLast(): boolean

Checks whether the data read position is after the last row.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

import { BusinessError } from '@ohos.base';

try {
  let resultSet: distributedKVStore.KVStoreResultSet;
  kvStore.getResultSet('batch_test_string_key').then((result) => {
    console.info('getResultSet succeed.');
    resultSet = result;
    let isafterlast = resultSet.isAfterLast();
    console.info("Check isAfterLast succeed:" + isafterlast);
  }).catch((err: BusinessError) => {
    console.error('getResultSet failed: ' + err);
  });
} catch (e) {
  console.error("Check isAfterLast failed: " + e);
}

getEntry

getEntry(): Entry

Obtains the KV pair from the current position.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

import { BusinessError } from '@ohos.base';

try {
  let resultSet: distributedKVStore.KVStoreResultSet;
  kvStore.getResultSet('batch_test_string_key').then((result) => {
    console.info('getResultSet succeed.');
    resultSet = result;
    let entry = resultSet.getEntry();
    console.info("getEntry succeed:" + JSON.stringify(entry));
  }).catch((err: BusinessError) => {
    console.error('getResultSet failed: ' + err);
  });
} catch (e) {
  console.error("getEntry failed: " + e);
}

Query

Provides methods to create a Query object, which defines different data query criteria. A Query object supports a maximum of 256 predicates.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

constructor

constructor()

A constructor used to create a Schema instance.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

reset

reset(): Query

Resets the Query object.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

import { BusinessError } from '@ohos.base';

try {
  let query: distributedKVStore.Query | null = new distributedKVStore.Query();
  query.equalTo("key", "value");
  console.info("query is " + query.getSqlLike());
  query.reset();
  console.info("query is " + query.getSqlLike());
  query = null;
} catch (e) {
  console.error("simply calls should be ok :" + e);
}

equalTo

equalTo(field: string, value: number|string|boolean): Query

Creates a Query object to match the specified field whose value is equal to the given value.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

import { BusinessError } from '@ohos.base';

try {
  let query: distributedKVStore.Query | null = new distributedKVStore.Query();
  query.equalTo("field", "value");
  console.info(`query is ${query.getSqlLike()}`);
  query = null;
} catch (e) {
  let error = e as BusinessError;
  console.error(`duplicated calls should be ok.code is ${error.code},message is ${error.message}`);
}

notEqualTo

notEqualTo(field: string, value: number|string|boolean): Query

Creates a Query object to match the specified field whose value is not equal to the specified value.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

import { BusinessError } from '@ohos.base';

try {
  let query: distributedKVStore.Query | null = new distributedKVStore.Query();
  query.notEqualTo("field", "value");
  console.info(`query is ${query.getSqlLike()}`);
  query = null;
} catch (e) {
  let error = e as BusinessError;
  console.error(`duplicated calls should be ok.code is ${error.code},message is ${error.message}`);
}

greaterThan

greaterThan(field: string, value: number|string|boolean): Query

Creates a Query object to match the specified field whose value is greater than the specified value.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

import { BusinessError } from '@ohos.base';

try {
    let query: distributedKVStore.Query | null = new distributedKVStore.Query();
    query.greaterThan("field", "value");
    console.info(`query is ${query.getSqlLike()}`);
    query = null;
} catch (e) {
    let error = e as BusinessError;
    console.error(`duplicated calls should be ok.code is ${error.code},message is ${error.message}`);
}

lessThan

lessThan(field: string, value: number|string): Query

Creates a Query object to match the specified field whose value is less than the specified value.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

import { BusinessError } from '@ohos.base';

try {
    let query: distributedKVStore.Query | null = new distributedKVStore.Query();
    query.lessThan("field", "value");
    console.info(`query is ${query.getSqlLike()}`);
    query = null;
} catch (e) {
    let error = e as BusinessError;
    console.error(`duplicated calls should be ok.code is ${error.code},message is ${error.message}`);
}

greaterThanOrEqualTo

greaterThanOrEqualTo(field: string, value: number|string): Query

Creates a Query object to match the specified field whose value is greater than or equal to the specified value.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

import { BusinessError } from '@ohos.base';

try {
    let query: distributedKVStore.Query | null = new distributedKVStore.Query();
    query.greaterThanOrEqualTo("field", "value");
    console.info(`query is ${query.getSqlLike()}`);
    query = null;
} catch (e) {
    let error = e as BusinessError;
    console.error(`duplicated calls should be ok.code is ${error.code},message is ${error.message}`);
}

lessThanOrEqualTo

lessThanOrEqualTo(field: string, value: number|string): Query

Creates a Query object to match the specified field whose value is less than or equal to the specified value.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

import { BusinessError } from '@ohos.base';

try {
    let query: distributedKVStore.Query | null = new distributedKVStore.Query();
    query.lessThanOrEqualTo("field", "value");
    console.info(`query is ${query.getSqlLike()}`);
    query = null;
} catch (e) {
    let error = e as BusinessError;
    console.error(`duplicated calls should be ok.code is ${error.code},message is ${error.message}`);
}

isNull

isNull(field: string): Query

Creates a Query object to match the specified field whose value is null.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

import { BusinessError } from '@ohos.base';

try {
    let query: distributedKVStore.Query | null = new distributedKVStore.Query();
    query.isNull("field");
    console.info(`query is ${query.getSqlLike()}`);
    query = null;
} catch (e) {
    let error = e as BusinessError;
    console.error(`duplicated calls should be ok.code is ${error.code},message is ${error.message}`);
}

inNumber

inNumber(field: string, valueList: number[]): Query

Creates a Query object to match the specified field whose value is within the specified list of numbers.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

import { BusinessError } from '@ohos.base';

try {
    let query: distributedKVStore.Query | null = new distributedKVStore.Query();
    query.inNumber("field", [0, 1]);
    console.info(`query is ${query.getSqlLike()}`);
    query = null;
} catch (e) {
    let error = e as BusinessError;
    console.error(`duplicated calls should be ok.code is ${error.code},message is ${error.message}`);
}

inString

inString(field: string, valueList: string[]): Query

Creates a Query object to match the specified field whose value is within the specified list of strings.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

import { BusinessError } from '@ohos.base';

try {
    let query: distributedKVStore.Query | null = new distributedKVStore.Query();
    query.inString("field", ['test1', 'test2']);
    console.info(`query is ${query.getSqlLike()}`);
    query = null;
} catch (e) {
    let error = e as BusinessError;
    console.error(`duplicated calls should be ok.code is ${error.code},message is ${error.message}`);
}

notInNumber

notInNumber(field: string, valueList: number[]): Query

Creates a Query object to match the specified field whose value is not within the specified list of numbers.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

import { BusinessError } from '@ohos.base';

try {
    let query: distributedKVStore.Query | null = new distributedKVStore.Query();
    query.notInNumber("field", [0, 1]);
    console.info(`query is ${query.getSqlLike()}`);
    query = null;
} catch (e) {
    let error = e as BusinessError;
    console.error(`duplicated calls should be ok.code is ${error.code},message is ${error.message}`);
}

notInString

notInString(field: string, valueList: string[]): Query

Creates a Query object to match the specified field whose value is not within the specified list of strings.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

import { BusinessError } from '@ohos.base';

try {
    let query: distributedKVStore.Query | null = new distributedKVStore.Query();
    query.notInString("field", ['test1', 'test2']);
    console.info(`query is ${query.getSqlLike()}`);
    query = null;
} catch (e) {
    let error = e as BusinessError;
    console.error(`duplicated calls should be ok.code is ${error.code},message is ${error.message}`);
}

like

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

Creates a Query object to match the specified field whose value is similar to the specified string.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

import { BusinessError } from '@ohos.base';

try {
    let query: distributedKVStore.Query | null = new distributedKVStore.Query();
    query.like("field", "value");
    console.info(`query is ${query.getSqlLike()}`);
    query = null;
} catch (e) {
    let error = e as BusinessError;
    console.error(`duplicated calls should be ok.code is ${error.code},message is ${error.message}`);
}

unlike

unlike(field: string, value: string): Query

Creates a Query object to match the specified field whose value is not similar to the specified string.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

import { BusinessError } from '@ohos.base';

try {
    let query: distributedKVStore.Query | null = new distributedKVStore.Query();
    query.unlike("field", "value");
    console.info(`query is ${query.getSqlLike()}`);
    query = null;
} catch (e) {
    let error = e as BusinessError;
    console.error(`duplicated calls should be ok.code is ${error.code},message is ${error.message}`);
}

and

and(): Query

Creates a Query object with the AND condition.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

import { BusinessError } from '@ohos.base';

try {
    let query: distributedKVStore.Query | null = new distributedKVStore.Query();
    query.notEqualTo("field", "value1");
    query.and();
    query.notEqualTo("field", "value2");
    console.info("query is " + query.getSqlLike());
    query = null;
} catch (e) {
    console.error("duplicated calls should be ok :" + e);
}

or

or(): Query

Creates a Query object with the OR condition.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

import { BusinessError } from '@ohos.base';

try {
    let query: distributedKVStore.Query | null = new distributedKVStore.Query();
    query.notEqualTo("field", "value1");
    query.or();
    query.notEqualTo("field", "value2");
    console.info("query is " + query.getSqlLike());
    query = null;
} catch (e) {
    console.error("duplicated calls should be ok :" + e);
}

orderByAsc

orderByAsc(field: string): Query

Creates a Query object to sort the query results in ascending order.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

import { BusinessError } from '@ohos.base';

try {
    let query: distributedKVStore.Query | null = new distributedKVStore.Query();
    query.notEqualTo("field", "value");
    query.orderByAsc("field");
    console.info(`query is ${query.getSqlLike()}`);
    query = null;
} catch (e) {
    let error = e as BusinessError;
    console.error(`duplicated calls should be ok.code is ${error.code},message is ${error.message}`);
}

orderByDesc

orderByDesc(field: string): Query

Creates a Query object to sort the query results in descending order.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

import { BusinessError } from '@ohos.base';

try {
    let query: distributedKVStore.Query | null = new distributedKVStore.Query();
    query.notEqualTo("field", "value");
    query.orderByDesc("field");
    console.info(`query is ${query.getSqlLike()}`);
    query = null;
} catch (e) {
    let error = e as BusinessError;
    console.error(`duplicated calls should be ok.code is ${error.code},message is ${error.message}`);
}

limit

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

Creates a Query object to specify the number of records of the query result and where to start. This API must be called after the invocation of the orderByAsc(), orderByDesc(), and the query APIs of the Query object.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

import { BusinessError } from '@ohos.base';

let total = 10;
let offset = 1;
try {
  let query: distributedKVStore.Query | null = new distributedKVStore.Query();
  query.notEqualTo("field", "value");
  query.limit(total, offset);
  console.info(`query is ${query.getSqlLike()}`);
  query = null;
} catch (e) {
  let error = e as BusinessError;
  console.error(`duplicated calls should be ok.code is ${error.code},message is ${error.message}`);
}

isNotNull

isNotNull(field: string): Query

Creates a Query object to match the specified field whose value is not null.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

import { BusinessError } from '@ohos.base';

try {
  let query: distributedKVStore.Query | null = new distributedKVStore.Query();
  query.isNotNull("field");
  console.info(`query is ${query.getSqlLike()}`);
  query = null;
} catch (e) {
  let error = e as BusinessError;
  console.error(`duplicated calls should be ok.code is ${error.code},message is ${error.message}`);
}

beginGroup

beginGroup(): Query

Creates a Query object for a query condition group with a left parenthesis.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

import { BusinessError } from '@ohos.base';

try {
    let query: distributedKVStore.Query | null = new distributedKVStore.Query();
    query.beginGroup();
    query.isNotNull("field");
    query.endGroup();
    console.info("query is " + query.getSqlLike());
    query = null;
} catch (e) {
    console.error("duplicated calls should be ok :" + e);
}

endGroup

endGroup(): Query

Creates a Query object for a query condition group with a right parenthesis.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

import { BusinessError } from '@ohos.base';

try {
    let query: distributedKVStore.Query | null = new distributedKVStore.Query();
    query.beginGroup();
    query.isNotNull("field");
    query.endGroup();
    console.info("query is " + query.getSqlLike());
    query = null;
} catch (e) {
    console.error("duplicated calls should be ok :" + e);
}

prefixKey

prefixKey(prefix: string): Query

Creates a Query object with a specified key prefix.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

import { BusinessError } from '@ohos.base';

try {
    let query: distributedKVStore.Query | null = new distributedKVStore.Query();
    query.prefixKey("$.name");
    query.prefixKey("0");
    console.info(`query is ${query.getSqlLike()}`);
    query = null;
} catch (e) {
    let error = e as BusinessError;
    console.error(`duplicated calls should be ok.code is ${error.code},message is ${error.message}`);
}

setSuggestIndex

setSuggestIndex(index: string): Query

Creates a Query object with an index preferentially used for query.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

import { BusinessError } from '@ohos.base';

try {
    let query: distributedKVStore.Query | null = new distributedKVStore.Query();
    query.setSuggestIndex("$.name");
    query.setSuggestIndex("0");
    console.info(`query is ${query.getSqlLike()}`);
    query = null;
} catch (e) {
    let error = e as BusinessError;
    console.error(`duplicated calls should be ok.code is ${error.code},message is ${error.message}`);
}

deviceId

deviceId(deviceId:string):Query

Creates a Query object with the device ID as the key prefix.

NOTE

deviceId can be obtained by deviceManager.getAvailableDeviceListSync. For details about how to obtain deviceId, see sync().

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

import { BusinessError } from '@ohos.base';

try {
    let query: distributedKVStore.Query | null = new distributedKVStore.Query();
    query.deviceId("deviceId");
    console.info(`query is ${query.getSqlLike()}`);
} catch (e) {
    let error = e as BusinessError;
    console.error(`duplicated calls should be ok.code is ${error.code},message is ${error.message}`);
}

getSqlLike

getSqlLike():string

Obtains the query statement of the Query object.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

import { BusinessError } from '@ohos.base';

try {
    let query: distributedKVStore.Query | null = new distributedKVStore.Query();
    let sql1 = query.getSqlLike();
    console.info(`GetSqlLike sql= ${sql1}`);
} catch (e) {
    console.error("duplicated calls should be ok : " + e);
}

SingleKVStore

Implements data management in a single KV store, such as adding data, deleting data, and subscribing to data changes or data synchronization completion.

Before calling any method in SingleKVStore, you must use getKVStore to obtain a SingleKVStore instance.

put

put(key: string, value: Uint8Array | string | number | boolean, callback: AsyncCallback<void>): void

Adds a KV pair of the specified type to this KV store. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

For details about the error codes, see RDB Error Codes.

Example

import { BusinessError } from '@ohos.base';

const KEY_TEST_STRING_ELEMENT = 'key_test_string';
const VALUE_TEST_STRING_ELEMENT = 'value-test-string';
try {
  kvStore.put(KEY_TEST_STRING_ELEMENT, VALUE_TEST_STRING_ELEMENT, (err) => {
    if (err != undefined) {
      console.error(`Failed to put.code is ${err.code},message is ${err.message}`);
      return;
    }
    console.info("Succeeded in putting");
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`An unexpected error occurred.code is ${error.code},message is ${error.message}`);
}

put

put(key: string, value: Uint8Array | string | number | boolean): Promise<void>

Adds a KV pair of the specified type to this KV store. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

For details about the error codes, see RDB Error Codes.

Example

import { BusinessError } from '@ohos.base';

const KEY_TEST_STRING_ELEMENT = 'key_test_string';
const VALUE_TEST_STRING_ELEMENT = 'value-test-string';
try {
  kvStore.put(KEY_TEST_STRING_ELEMENT, VALUE_TEST_STRING_ELEMENT).then(() => {
    console.info(`Succeeded in putting data`);
  }).catch((err: BusinessError) => {
    console.error(`Failed to put.code is ${err.code},message is ${err.message}`);
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`An unexpected error occurred.code is ${error.code},message is ${error.message}`);
}

putBatch

putBatch(entries: Entry[], callback: AsyncCallback<void>): void

Batch inserts KV pairs to this single KV store. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

For details about the error codes, see RDB Error Codes.

Example

import { BusinessError } from '@ohos.base';

try {
  let entries: distributedKVStore.Entry[] = [];
  for (let i = 0; i < 10; i++) {
    let key = 'batch_test_string_key';
    let entry: distributedKVStore.Entry = {
      key: key + i,
      value: {
        type: distributedKVStore.ValueType.STRING,
        value: 'batch_test_string_value'
      }
    }
    entries.push(entry);
  }
  console.info(`entries: ${entries}`);
  kvStore.putBatch(entries, async (err) => {
    if (err != undefined) {
      console.error(`Failed to put Batch.code is ${err.code},message is ${err.message}`);
      return;
    }
    console.info('Succeeded in putting Batch');
    if (kvStore != null) {
      kvStore.getEntries('batch_test_string_key', (err, entries) => {
        if (err != undefined) {
          console.error(`Failed to get Entries.code is ${err.code},message is ${err.message}`);
        }
        console.info('Succeeded in getting Entries');
        console.info(`entries.length: ${entries.length}`);
        console.info(`entries[0]: ${entries[0]}`);
      });
    } else {
      console.error('KvStore is null'); // The subsequent sample code is the same as the code here.
    }
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`An unexpected error occurred.code is ${error.code},message is ${error.message} `);
}

putBatch

putBatch(entries: Entry[]): Promise<void>

Batch inserts KV pairs to this single KV store. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

For details about the error codes, see RDB Error Codes.

Example

import { BusinessError } from '@ohos.base';

try {
  let entries: distributedKVStore.Entry[] = [];
  for (let i = 0; i < 10; i++) {
    let key = 'batch_test_string_key';
    let entry: distributedKVStore.Entry = {
      key: key + i,
      value: {
        type: distributedKVStore.ValueType.STRING,
        value: 'batch_test_string_value'
      }
    }
    entries.push(entry);
  }
  console.info(`entries: ${entries}`);
  kvStore.putBatch(entries).then(async () => {
    console.info('Succeeded in putting Batch');
    if (kvStore != null) {
      kvStore.getEntries('batch_test_string_key').then((entries) => {
        console.info('Succeeded in getting Entries');
        console.info(`PutBatch ${entries}`);
      }).catch((err: BusinessError) => {
        console.error(`Failed to get Entries.code is ${err.code},message is ${err.message}`);
      });
    }
  }).catch((err: BusinessError) => {
    console.error(`Failed to put Batch.code is ${err.code},message is ${err.message}`);
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`An unexpected error occurred.code is ${error.code},message is ${error.message} `);
}

putBatch

putBatch(value: Array<ValuesBucket>, callback: AsyncCallback<void>): void

Writes data to this single KV store. This API uses an asynchronous callback to return the result.

Model restriction: This API can be used only in the stage model.

System API: This is a system API.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

For details about the error codes, see RDB Error Codes.

Example

import { BusinessError } from '@ohos.base';

try {
  let v8Arr: distributedKVStore.Entry[] = [];
  let arr = new Uint8Array([4, 5, 6, 7]);
  let vb1: distributedKVStore.Entry = { key: "name_1", value: 32 }
  let vb2: distributedKVStore.Entry = { key: "name_2", value: arr };
  let vb3: distributedKVStore.Entry = { key: "name_3", value: "lisi" };

  v8Arr.push(vb1);
  v8Arr.push(vb2);
  v8Arr.push(vb3);
  kvStore.putBatch(v8Arr, async (err) => {
    if (err != undefined) {
      console.error(`Failed to put batch.code is ${err.code},message is ${err.message}`);
      return;
    }
    console.info('Succeeded in putting batch');
  })
} catch (e) {
  let error = e as BusinessError;
  console.error(`Failed to put batch.code is ${error.code},message is ${error.message}`);
}

putBatch

putBatch(value: Array<ValuesBucket>): Promise<void>

Write data to this KV store. This API uses a promise to return the result.

Model restriction: This API can be used only in the stage model.

System API: This is a system API.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

For details about the error codes, see RDB Error Codes.

Example

import { BusinessError } from '@ohos.base';

try {
  let v8Arr: distributedKVStore.Entry[] = [];
  let arr = new Uint8Array([4, 5, 6, 7]);
  let vb1: distributedKVStore.Entry = { key: "name_1", value: 32 }
  let vb2: distributedKVStore.Entry = { key: "name_2", value: arr };
  let vb3: distributedKVStore.Entry = { key: "name_3", value: "lisi" };

  v8Arr.push(vb1);
  v8Arr.push(vb2);
  v8Arr.push(vb3);
  kvStore.putBatch(v8Arr).then(async () => {
    console.info(`Succeeded in putting patch`);
  }).catch((err: BusinessError) => {
    console.error(`putBatch fail.code is ${err.code},message is ${err.message}`);
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`putBatch fail.code is ${error.code},message is ${error.message}`);
}

delete

delete(key: string, callback: AsyncCallback<void>): void

Deletes a KV pair from this KV store. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

For details about the error codes, see RDB Error Codes.

Example

import { BusinessError } from '@ohos.base';

const KEY_TEST_STRING_ELEMENT = 'key_test_string';
const VALUE_TEST_STRING_ELEMENT = 'value-test-string';
try {
  kvStore.put(KEY_TEST_STRING_ELEMENT, VALUE_TEST_STRING_ELEMENT, (err) => {
    if (err != undefined) {
      console.error(`Failed to put.code is ${err.code},message is ${err.message}`);
      return;
    }
    console.info('Succeeded in putting');
    if (kvStore != null) {
      kvStore.delete(KEY_TEST_STRING_ELEMENT, (err) => {
        if (err != undefined) {
          console.error(`Failed to delete.code is ${err.code},message is ${err.message}`);
          return;
        }
        console.info('Succeeded in deleting');
      });
    }
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`An unexpected error occurred.code is ${error.code},message is ${error.message}`);
}

delete

delete(key: string): Promise<void>

Deletes a KV pair from this KV store. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

For details about the error codes, see RDB Error Codes.

Example

import { BusinessError } from '@ohos.base';

const KEY_TEST_STRING_ELEMENT = 'key_test_string';
const VALUE_TEST_STRING_ELEMENT = 'value-test-string';
try {
  kvStore.put(KEY_TEST_STRING_ELEMENT, VALUE_TEST_STRING_ELEMENT).then(() => {
    console.info(`Succeeded in putting data`);
    if (kvStore != null) {
      kvStore.delete(KEY_TEST_STRING_ELEMENT).then(() => {
        console.info('Succeeded in deleting');
      }).catch((err: BusinessError) => {
        console.error(`Failed to delete.code is ${err.code},message is ${err.message}`);
      });
    }
  }).catch((err: BusinessError) => {
    console.error(`Failed to put.code is ${err.code},message is ${err.message}`);
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`An unexpected error occurred.code is ${error.code},message is ${error.message}`);
}

delete

delete(predicates: dataSharePredicates.DataSharePredicates, callback: AsyncCallback<void>)

Deletes KV pairs from this KV store. This API uses an asynchronous callback to return the result.

Model restriction: This API can be used only in the stage model.

System API: This is a system API.

System capability: SystemCapability.DistributedDataManager.DataShare.Provider

Parameters

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

For details about the error codes, see RDB Error Codes.

Example

import dataSharePredicates from '@ohos.data.dataSharePredicates';
import { BusinessError } from '@ohos.base';

try {
  let predicates = new dataSharePredicates.DataSharePredicates();
  let arr = ["name"];
  predicates.inKeys(arr);
  kvStore.put("name", "bob", (err) => {
    if (err != undefined) {
      console.error(`Failed to put.code is ${err.code},message is ${err.message}`);
      return;
    }
    console.info("Succeeded in putting");
    if (kvStore != null) {
      kvStore.delete(predicates, (err) => {
        if (err == undefined) {
          console.info('Succeeded in deleting');
        } else {
          console.error(`Failed to delete.code is ${err.code},message is ${err.message}`);
        }
      });
    }
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`An unexpected error occurred.code is ${error.code},message is ${error.message}`);
}

delete

delete(predicates: dataSharePredicates.DataSharePredicates): Promise<void>

Deletes KV pairs from this KV store. This API uses a promise to return the result.

Model restriction: This API can be used only in the stage model.

System API: This is a system API.

System capability: SystemCapability.DistributedDataManager.DataShare.Provider

Parameters

Return value

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

For details about the error codes, see RDB Error Codes.

Example

import dataSharePredicates from '@ohos.data.dataSharePredicates';
import { BusinessError } from '@ohos.base';

try {
  let predicates = new dataSharePredicates.DataSharePredicates();
  let arr = ["name"];
  predicates.inKeys(arr);
  kvStore.put("name", "bob").then(() => {
    console.info(`Succeeded in putting data`);
    if (kvStore != null) {
      kvStore.delete(predicates).then(() => {
        console.info('Succeeded in deleting');
      }).catch((err: BusinessError) => {
        console.error(`Failed to delete.code is ${err.code},message is ${err.message}`);
      });
    }
  }).catch((err: BusinessError) => {
    console.error(`Failed to put.code is ${err.code},message is ${err.message}`);
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`An unexpected error occurred.code is ${error.code},message is ${error.message}`);
}

deleteBatch

deleteBatch(keys: string[], callback: AsyncCallback<void>): void

Batch deletes KV pairs from this single KV store. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

For details about the error codes, see RDB Error Codes.

Example

import { BusinessError } from '@ohos.base';

try {
  let entries: distributedKVStore.Entry[] = [];
  let keys: string[] = [];
  for (let i = 0; i < 5; i++) {
    let key = 'batch_test_string_key';
    let entry: distributedKVStore.Entry = {
      key: key + i,
      value: {
        type: distributedKVStore.ValueType.STRING,
        value: 'batch_test_string_value'
      }
    }
    entries.push(entry);
    keys.push(key + i);
  }
  console.info(`entries: ${entries}`);
  kvStore.putBatch(entries, async (err) => {
    if (err != undefined) {
      console.error(`Failed to put Batch.code is ${err.code},message is ${err.message}`);
      return;
    }
    console.info('Succeeded in putting Batch');
    if (kvStore != null) {
      kvStore.deleteBatch(keys, async (err) => {
        if (err != undefined) {
          console.error(`Failed to delete Batch.code is ${err.code},message is ${err.message}`);
          return;
        }
        console.info('Succeeded in deleting Batch');
      });
    }
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`An unexpected error occurred.code is ${error.code},message is ${error.message}`);
}

deleteBatch

deleteBatch(keys: string[]): Promise<void>

Batch deletes KV pairs from this single KV store. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

For details about the error codes, see RDB Error Codes.

Example

import { BusinessError } from '@ohos.base';

try {
  let entries: distributedKVStore.Entry[] = [];
  let keys: string[] = [];
  for (let i = 0; i < 5; i++) {
    let key = 'batch_test_string_key';
    let entry: distributedKVStore.Entry = {
      key: key + i,
      value: {
        type: distributedKVStore.ValueType.STRING,
        value: 'batch_test_string_value'
      }
    }
    entries.push(entry);
    keys.push(key + i);
  }
  console.info(`entries: ${entries}`);
  kvStore.putBatch(entries).then(async () => {
    console.info('Succeeded in putting Batch');
    if (kvStore != null) {
      kvStore.deleteBatch(keys).then(() => {
        console.info('Succeeded in deleting Batch');
      }).catch((err: BusinessError) => {
        console.error(`Failed to delete Batch.code is ${err.code},message is ${err.message}`);
      });
    }
  }).catch((err: BusinessError) => {
    console.error(`Failed to put Batch.code is ${err.code},message is ${err.message}`);
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`An unexpected error occurred.code is ${error.code},message is ${error.message}`);
}

removeDeviceData

removeDeviceData(deviceId: string, callback: AsyncCallback<void>): void

Deletes data of a device. This API uses an asynchronous callback to return the result.

NOTE

deviceId can be obtained by deviceManager.getAvailableDeviceListSync. For details about how to obtain deviceId, see sync().

System capability: SystemCapability.DistributedDataManager.KVStore.DistributedKVStore

Parameters

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

Example

import { BusinessError } from '@ohos.base';

const KEY_TEST_STRING_ELEMENT = 'key_test_string_2';
const VALUE_TEST_STRING_ELEMENT = 'value-string-002';
try {
  kvStore.put(KEY_TEST_STRING_ELEMENT, VALUE_TEST_STRING_ELEMENT, async (err) => {
    console.info('Succeeded in putting data');
    const deviceid = 'no_exist_device_id';
    if (kvStore != null) {
      kvStore.removeDeviceData(deviceid, async (err) => {
        if (err == undefined) {
          console.info('succeeded in removing device data');
        } else {
          console.error(`Failed to remove device data.code is ${err.code},message is ${err.message} `);
          if (kvStore != null) {
            kvStore.get(KEY_TEST_STRING_ELEMENT, async (err, data) => {
              console.info('Succeeded in getting data');
            });
          }
        }
      });
    }
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`An unexpected error occurred.code is ${error.code},message is ${error.message}`)
}

removeDeviceData

removeDeviceData(deviceId: string): Promise<void>

Deletes data of a device. This API uses a promise to return the result.

NOTE

deviceId can be obtained by deviceManager.getAvailableDeviceListSync. For details about how to obtain deviceId, see sync().

System capability: SystemCapability.DistributedDataManager.KVStore.DistributedKVStore

Parameters

Return value

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

Example

import { BusinessError } from '@ohos.base';

const KEY_TEST_STRING_ELEMENT = 'key_test_string_2';
const VALUE_TEST_STRING_ELEMENT = 'value-string-001';
try {
  kvStore.put(KEY_TEST_STRING_ELEMENT, VALUE_TEST_STRING_ELEMENT).then(() => {
    console.info('Succeeded in putting data');
  }).catch((err: BusinessError) => {
    console.error(`Failed to put data.code is ${err.code},message is ${err.message} `);
  });
  const deviceid = 'no_exist_device_id';
  kvStore.removeDeviceData(deviceid).then(() => {
    console.info('succeeded in removing device data');
  }).catch((err: BusinessError) => {
    console.error(`Failed to remove device data.code is ${err.code},message is ${err.message} `);
  });
  kvStore.get(KEY_TEST_STRING_ELEMENT).then((data) => {
    console.info('Succeeded in getting data');
  }).catch((err: BusinessError) => {
    console.error(`Failed to get data.code is ${err.code},message is ${err.message} `);
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`An unexpected error occurred.code is ${error.code},message is ${error.message}`)
}

get

get(key: string, callback: AsyncCallback<boolean | string | number | Uint8Array>): void

Obtains the value of the specified key. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

Example

import { BusinessError } from '@ohos.base';


const KEY_TEST_STRING_ELEMENT = 'key_test_string';
const VALUE_TEST_STRING_ELEMENT = 'value-test-string';
try {
  kvStore.put(KEY_TEST_STRING_ELEMENT, VALUE_TEST_STRING_ELEMENT, (err) => {
    if (err != undefined) {
      console.error(`Failed to put.code is ${err.code},message is ${err.message}`);
      return;
    }
    console.info("Succeeded in putting");
    if (kvStore != null) {
      kvStore.get(KEY_TEST_STRING_ELEMENT, (err, data) => {
        if (err != undefined) {
          console.error(`Failed to get.code is ${err.code},message is ${err.message}`);
          return;
        }
        console.info(`Succeeded in getting data.data=${data}`);
      });
    }
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`Failed to get.code is ${error.code},message is ${error.message}`);
}

get

get(key: string): Promise<boolean | string | number | Uint8Array>

Obtains the value of the specified key. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

Example

import { BusinessError } from '@ohos.base';


const KEY_TEST_STRING_ELEMENT = 'key_test_string';
const VALUE_TEST_STRING_ELEMENT = 'value-test-string';
try {
  kvStore.put(KEY_TEST_STRING_ELEMENT, VALUE_TEST_STRING_ELEMENT).then(() => {
    console.info(`Succeeded in putting data`);
    if (kvStore != null) {
      kvStore.get(KEY_TEST_STRING_ELEMENT).then((data) => {
        console.info(`Succeeded in getting data.data=${data}`);
      }).catch((err: BusinessError) => {
        console.error(`Failed to get.code is ${err.code},message is ${err.message}`);
      });
    }
  }).catch((err: BusinessError) => {
    console.error(`Failed to put.code is ${err.code},message is ${err.message}`);
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`Failed to get.code is ${error.code},message is ${error.message}`);
}

getEntries

getEntries(keyPrefix: string, callback: AsyncCallback<Entry[]>): void

Obtains all KV pairs that match the specified key prefix. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

Example

import { BusinessError } from '@ohos.base';

try {
  let entries: distributedKVStore.Entry[] = [];
  for (let i = 0; i < 10; i++) {
    let key = 'batch_test_string_key';
    let entry: distributedKVStore.Entry = {
      key: key + i,
      value: {
        type: distributedKVStore.ValueType.STRING,
        value: 'batch_test_string_value'
      }
    }
    entries.push(entry);
  }
  console.info(`entries: ${entries}`);
  kvStore.putBatch(entries, async (err) => {
    if (err != undefined) {
      console.error(`Failed to put Batch.code is ${err.code},message is ${err.message}`);
      return;
    }
    console.info('Succeeded in putting Batch');
    if (kvStore != null) {
      kvStore.getEntries('batch_test_string_key', (err, entries) => {
        if (err != undefined) {
          console.error(`Failed to get Entries.code is ${err.code},message is ${err.message}`);
          return;
        }
        console.info('Succeeded in getting Entries');
        console.info(`entries.length: ${entries.length}`);
        console.info(`entries[0]: ${entries[0]}`);
      });
    }
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`An unexpected error occurred.code is ${error.code},message is ${error.message} `);
}

getEntries

getEntries(keyPrefix: string): Promise<Entry[]>

Obtains all KV pairs that match the specified key prefix. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

Example

import { BusinessError } from '@ohos.base';


try {
  let entries: distributedKVStore.Entry[] = [];
  for (let i = 0; i < 10; i++) {
    let key = 'batch_test_string_key';
    let entry: distributedKVStore.Entry = {
      key: key + i,
      value: {
        type: distributedKVStore.ValueType.STRING,
        value: 'batch_test_string_value'
      }
    }
    entries.push(entry);
  }
  console.info(`entries: ${entries}`);
  kvStore.putBatch(entries).then(async () => {
    console.info('Succeeded in putting Batch');
    if (kvStore != null) {
      kvStore.getEntries('batch_test_string_key').then((entries) => {
        console.info('Succeeded in getting Entries');
        console.info(`PutBatch ${entries}`);
      }).catch((err: BusinessError) => {
        console.error(`Failed to get Entries.code is ${err.code},message is ${err.message}`);
      });
    }
  }).catch((err: BusinessError) => {
    console.error(`Failed to put Batch.code is ${err.code},message is ${err.message}`);
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`An unexpected error occurred.code is ${error.code},message is ${error.message} `);
}

getEntries

getEntries(query: Query, callback: AsyncCallback<Entry[]>): void

Obtains the KV pairs that match the specified Query object. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

Example

import { BusinessError } from '@ohos.base';

try {
  let arr = new Uint8Array([21, 31]);
  let entries: distributedKVStore.Entry[] = [];
  for (let i = 0; i < 10; i++) {
    let key = 'batch_test_bool_key';
    let entry: distributedKVStore.Entry = {
      key: key + i,
      value: {
        type: distributedKVStore.ValueType.BYTE_ARRAY,
        value: arr
      }
    }
    entries.push(entry);
  }
  console.info(`entries: {entries}`);
  kvStore.putBatch(entries, async (err) => {
    console.info('Succeeded in putting Batch');
    const query = new distributedKVStore.Query();
    query.prefixKey("batch_test");
    if (kvStore != null) {
      kvStore.getEntries(query, (err, entries) => {
        if (err != undefined) {
          console.error(`Failed to get Entries.code is ${err.code},message is ${err.message}`);
          return;
        }
        console.info('Succeeded in getting Entries');
        console.info(`entries.length: ${entries.length}`);
        console.info(`entries[0]: ${entries[0]}`);
      });
    }
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`Failed to get Entries.code is ${error.code},message is ${error.message}`);
}

getEntries

getEntries(query: Query): Promise<Entry[]>

Obtains the KV pairs that match the specified Query object. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

Example

import { BusinessError } from '@ohos.base';

try {
  let arr = new Uint8Array([21, 31]);
  let entries: distributedKVStore.Entry[] = [];
  for (let i = 0; i < 10; i++) {
    let key = 'batch_test_bool_key';
    let entry: distributedKVStore.Entry = {
      key: key + i,
      value: {
        type: distributedKVStore.ValueType.BYTE_ARRAY,
        value: arr
      }
    }
    entries.push(entry);
  }
  console.info(`entries: {entries}`);
  kvStore.putBatch(entries).then(async () => {
    console.info('Succeeded in putting Batch');
    const query = new distributedKVStore.Query();
    query.prefixKey("batch_test");
    if (kvStore != null) {
      kvStore.getEntries(query).then((entries) => {
        console.info('Succeeded in getting Entries');
      }).catch((err: BusinessError) => {
        console.error(`Failed to get Entries.code is ${err.code},message is ${err.message}`);
      });
    }
  }).catch((err: BusinessError) => {
    console.error(`Failed to get Entries.code is ${err.code},message is ${err.message}`)
  });
  console.info('Succeeded in getting Entries');
} catch (e) {
  let error = e as BusinessError;
  console.error(`Failed to get Entries.code is ${error.code},message is ${error.message}`);
}

getResultSet

getResultSet(keyPrefix: string, callback: AsyncCallback<KVStoreResultSet>): void

Obtains a result set with the specified prefix from this single KV store. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

Example

import { BusinessError } from '@ohos.base';

try {
  let resultSet: distributedKVStore.KVStoreResultSet;
  let entries: distributedKVStore.Entry[] = [];
  for (let i = 0; i < 10; i++) {
    let key = 'batch_test_string_key';
    let entry: distributedKVStore.Entry = {
      key: key + i,
      value: {
        type: distributedKVStore.ValueType.STRING,
        value: 'batch_test_string_value'
      }
    }
    entries.push(entry);
  }
  kvStore.putBatch(entries, async (err) => {
    if (err != undefined) {
      console.error(`Failed to put batch.code is ${err.code},message is ${err.message}`);
      return;
    }
    console.info('Succeeded in putting batch');
    if (kvStore != null) {
      kvStore.getResultSet('batch_test_string_key', async (err, result) => {
        if (err != undefined) {
          console.error(`Failed to get resultset.code is ${err.code},message is ${err.message}`);
          return;
        }
        console.info('Succeeded in getting result set');
        resultSet = result;
        if (kvStore != null) {
          kvStore.closeResultSet(resultSet, (err) => {
            if (err != undefined) {
              console.error(`Failed to close resultset.code is ${err.code},message is ${err.message}`);
              return;
            }
            console.info('Succeeded in closing result set');
          });
        }
      });
    }
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`An unexpected error occurred.code is ${error.code},message is ${error.message}`);
}

getResultSet

getResultSet(keyPrefix: string): Promise<KVStoreResultSet>

Obtains a result set with the specified prefix from this single KV store. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

Example

import { BusinessError } from '@ohos.base';

try {
  let resultSet: distributedKVStore.KVStoreResultSet;
  let entries: distributedKVStore.Entry[] = [];
  for (let i = 0; i < 10; i++) {
    let key = 'batch_test_string_key';
    let entry: distributedKVStore.Entry = {
      key: key + i,
      value: {
        type: distributedKVStore.ValueType.STRING,
        value: 'batch_test_string_value'
      }
    }
    entries.push(entry);
  }
  kvStore.putBatch(entries).then(async () => {
    console.info('Succeeded in putting batch');
  }).catch((err: BusinessError) => {
    console.error(`Failed to put batch.code is ${err.code},message is ${err.message}`);
  });
  kvStore.getResultSet('batch_test_string_key').then((result) => {
    console.info('Succeeded in getting result set');
    resultSet = result;
    if (kvStore != null) {
      kvStore.closeResultSet(resultSet).then(() => {
        console.info('Succeeded in closing result set');
      }).catch((err: BusinessError) => {
        console.error(`Failed to close resultset.code is ${err.code},message is ${err.message}`);
      });
    }
  }).catch((err: BusinessError) => {
    console.error(`Failed to get resultset.code is ${err.code},message is ${err.message}`);
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`An unexpected error occurred.code is ${error.code},message is ${error.code}`);
}

getResultSet

getResultSet(query: Query, callback: AsyncCallback<KVStoreResultSet>): void

Obtains a KVStoreResultSet object that matches the specified Query object. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

Example

import { BusinessError } from '@ohos.base';

try {
  let resultSet: distributedKVStore.KVStoreResultSet;
  let entries: distributedKVStore.Entry[] = [];
  for (let i = 0; i < 10; i++) {
    let key = 'batch_test_string_key';
    let entry: distributedKVStore.Entry = {
      key: key + i,
      value: {
        type: distributedKVStore.ValueType.STRING,
        value: 'batch_test_string_value'
      }
    }
    entries.push(entry);
  }
  kvStore.putBatch(entries, async (err) => {
    if (err != undefined) {
      console.error(`Failed to put batch.code is ${err.code},message is ${err.message}`);
      return;
    }
    console.info('Succeeded in putting batch');
    const query = new distributedKVStore.Query();
    query.prefixKey("batch_test");
    if (kvStore != null) {
      kvStore.getResultSet(query, async (err, result) => {
        if (err != undefined) {
          console.error(`Failed to get resultset.code is ${err.code},message is ${err.message}`);
          return;
        }
        console.info('Succeeded in getting result set');
      });
    }
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`An unexpected error occurred.code is ${error.code},message is ${error.message}`);
}

getResultSet

getResultSet(query: Query): Promise<KVStoreResultSet>

Obtains a KVStoreResultSet object that matches the specified Query object. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

Example

import { BusinessError } from '@ohos.base';

try {
  let resultSet: distributedKVStore.KVStoreResultSet;
  let entries: distributedKVStore.Entry[] = [];
  for (let i = 0; i < 10; i++) {
    let key = 'batch_test_string_key';
    let entry: distributedKVStore.Entry = {
      key: key + i,
      value: {
        type: distributedKVStore.ValueType.STRING,
        value: 'batch_test_string_value'
      }
    }
    entries.push(entry);
  }
  kvStore.putBatch(entries).then(async () => {
    console.info('Succeeded in putting batch');
  }).catch((err: BusinessError) => {
    console.error(`Failed to put batch.code is ${err.code},message is ${err.message}`);
  });
  const query = new distributedKVStore.Query();
  query.prefixKey("batch_test");
  kvStore.getResultSet(query).then((result) => {
    console.info('Succeeded in getting result set');
    resultSet = result;
  }).catch((err: BusinessError) => {
    console.error(`Failed to get resultset.code is ${err.code},message is ${err.message}`);
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`An unexpected error occurred.code is ${error.code},message is ${error.code}`);
}

getResultSet

getResultSet(predicates: dataSharePredicates.DataSharePredicates, callback: AsyncCallback<KVStoreResultSet>): void

Obtains a KVStoreResultSet object that matches the specified predicate object. This API uses an asynchronous callback to return the result.

Model restriction: This API can be used only in the stage model.

System API: This is a system API.

System capability: SystemCapability.DistributedDataManager.DataShare.Provider

Parameters

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

Example

import dataSharePredicates from '@ohos.data.dataSharePredicates';
import { BusinessError } from '@ohos.base';

try {
  let resultSet: distributedKVStore.KVStoreResultSet;
  let predicates = new dataSharePredicates.DataSharePredicates();
  predicates.prefixKey("batch_test_string_key");
  kvStore.getResultSet(predicates, async (err, result) => {
    if (err != undefined) {
      console.error(`Failed to get resultset.code is ${err.code},message is ${err.message}`);
      return;
    }
    console.info('Succeeded in getting result set');
    resultSet = result;
    if (kvStore != null) {
      kvStore.closeResultSet(resultSet, (err) => {
        if (err != undefined) {
          console.error(`Failed to close resultset.code is ${err.code},message is ${err.message}`);
          return;
        }
        console.info('Succeeded in closing result set');
      });
    }
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`An unexpected error occurred.code is ${error.code},message is ${error.code}`);
}

getResultSet

getResultSet(predicates: dataSharePredicates.DataSharePredicates): Promise<KVStoreResultSet>

Obtains a KVStoreResultSet object that matches the specified predicate object. This API uses a promise to return the result.

Model restriction: This API can be used only in the stage model.

System API: This is a system API.

System capability: SystemCapability.DistributedDataManager.DataShare.Provider

Parameters

Return value

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

Example

import dataSharePredicates from '@ohos.data.dataSharePredicates';
import { BusinessError } from '@ohos.base';

try {
  let resultSet: distributedKVStore.KVStoreResultSet;
  let predicates = new dataSharePredicates.DataSharePredicates();
  predicates.prefixKey("batch_test_string_key");
  kvStore.getResultSet(predicates).then((result) => {
    console.info('Succeeded in getting result set');
    resultSet = result;
    if (kvStore != null) {
      kvStore.closeResultSet(resultSet).then(() => {
        console.info('Succeeded in closing result set');
      }).catch((err: BusinessError) => {
        console.error(`Failed to close resultset.code is ${err.code},message is ${err.message}`);
      });
    }
  }).catch((err: BusinessError) => {
    console.error(`Failed to get resultset.code is ${err.code},message is ${err.message}`);
  });

} catch (e) {
  let error = e as BusinessError;
  console.error(`An unexpected error occurred.code is ${error.code},message is ${error.code}`);
}

closeResultSet

closeResultSet(resultSet: KVStoreResultSet, callback: AsyncCallback<void>): void

Closes the KVStoreResultSet object returned by SingleKvStore.getResultSet. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Example

import { BusinessError } from '@ohos.base';

let resultSet: distributedKVStore.KVStoreResultSet;
try {
  kvStore.getResultSet('batch_test_string_key', async (err, result) => {
    if (err != undefined) {
      console.error(`Failed to get resultset.code is ${err.code},message is ${err.message}`);
      return;
    }
    console.info('Succeeded in getting result set');
    resultSet = result;
    if (kvStore != null) {
      kvStore.closeResultSet(resultSet, (err) => {
        if (err != undefined) {
          console.error(`Failed to close resultset.code is ${err.code},message is ${err.message}`);
          return;
        }
        console.info('Succeeded in closing result set');
      })
    }
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`An unexpected error occurred.code is ${error.code},message is ${error.code}`);
}

closeResultSet

closeResultSet(resultSet: KVStoreResultSet): Promise<void>

Closes the KVStoreResultSet object returned by SingleKvStore.getResultSet. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

import { BusinessError } from '@ohos.base';

let resultSet: distributedKVStore.KVStoreResultSet;
try {
  kvStore.getResultSet('batch_test_string_key').then((result) => {
    console.info('Succeeded in getting result set');
    resultSet = result;
    if (kvStore != null) {
      kvStore.closeResultSet(resultSet).then(() => {
        console.info('Succeeded in closing result set');
      }).catch((err: BusinessError) => {
        console.error(`Failed to close resultset.code is ${err.code},message is ${err.message}`);
      });
    }
  }).catch((err: BusinessError) => {
    console.error(`Failed to get resultset.code is ${err.code},message is ${err.message}`);
  });

} catch (e) {
  let error = e as BusinessError;
  console.error(`An unexpected error occurred.code is ${error.code},message is ${error.code}`);
}

getResultSize

getResultSize(query: Query, callback: AsyncCallback<number>): void

Obtains the number of results that matches the specified Query object. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

Example

import { BusinessError } from '@ohos.base';

try {
  let entries: distributedKVStore.Entry[] = [];
  for (let i = 0; i < 10; i++) {
    let key = 'batch_test_string_key';
    let entry: distributedKVStore.Entry = {
      key: key + i,
      value: {
        type: distributedKVStore.ValueType.STRING,
        value: 'batch_test_string_value'
      }
    }
    entries.push(entry);
  }
  kvStore.putBatch(entries, async (err) => {
    console.info('Succeeded in putting batch');
    const query = new distributedKVStore.Query();
    query.prefixKey("batch_test");
    if (kvStore != null) {
      kvStore.getResultSize(query, async (err, resultSize) => {
        if (err != undefined) {
          console.error(`Failed to get result size.code is ${err.code},message is ${err.message}`);
          return;
        }
        console.info('Succeeded in getting result set size');
      });
    }
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`An unexpected error occurred.code is ${error.code},message is ${error.code}`);
}

getResultSize

getResultSize(query: Query): Promise<number>

Obtains the number of results that matches the specified Query object. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

Example

import { BusinessError } from '@ohos.base';

try {
  let entries: distributedKVStore.Entry[] = [];
  for (let i = 0; i < 10; i++) {
    let key = 'batch_test_string_key';
    let entry: distributedKVStore.Entry = {
      key: key + i,
      value: {
        type: distributedKVStore.ValueType.STRING,
        value: 'batch_test_string_value'
      }
    }
    entries.push(entry);
  }
  kvStore.putBatch(entries).then(async () => {
    console.info('Succeeded in putting batch');
  }).catch((err: BusinessError) => {
    console.error(`Failed to put batch.code is ${err.code},message is ${err.message}`);
  });
  const query = new distributedKVStore.Query();
  query.prefixKey("batch_test");
  kvStore.getResultSize(query).then((resultSize) => {
    console.info('Succeeded in getting result set size');
  }).catch((err: BusinessError) => {
    console.error(`Failed to get result size.code is ${err.code},message is ${err.message}`);
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`An unexpected error occurred.code is ${error.code},message is ${error.code}`);
}

backup

backup(file:string, callback: AsyncCallback<void>):void

Backs up a distributed KV store. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

Example

import { BusinessError } from '@ohos.base';

let file = "BK001";
try {
  kvStore.backup(file, (err) => {
    if (err) {
      console.error(`Failed to backup.code is ${err.code},message is ${err.message} `);
    } else {
      console.info(`Succeeded in backupping data`);
    }
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`An unexpected error occurred.code is ${error.code},message is ${error.message}`);
}

backup

backup(file:string): Promise<void>

Backs up an RDB store. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

Example

import { BusinessError } from '@ohos.base';

let file = "BK001";
try {
  kvStore.backup(file).then(() => {
    console.info(`Succeeded in backupping data`);
  }).catch((err: BusinessError) => {
    console.error(`Failed to backup.code is ${err.code},message is ${err.message}`);
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`An unexpected error occurred.code is ${error.code},message is ${error.message}`);
}

restore

restore(file:string, callback: AsyncCallback<void>):void

Restores a distributed KV store from a database file. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

Example

import { BusinessError } from '@ohos.base';

let file = "BK001";
try {
  kvStore.restore(file, (err) => {
    if (err) {
      console.error(`Failed to restore.code is ${err.code},message is ${err.message}`);
    } else {
      console.info(`Succeeded in restoring data`);
    }
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`An unexpected error occurred.code is ${error.code},message is ${error.message}`);
}

restore

restore(file:string): Promise<void>

Restores a distributed KV store from a database file. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Error codes

For details about the error codes, see Distributed KV Store Error Codes.

Example

import { BusinessError } from '@ohos.base';

let file = "BK001";
try {
  kvStore.restore(file).then(() => {
    console.info(`Succeeded in restoring data`);
  }).catch((err: BusinessError) => {
    console.error(`Failed to restore.code is ${err.code},message is ${err.message}`);
  });
} catch (e) {
  let error = e as BusinessError;
  console.error(`An unexpected error occurred.code is ${error.code},message is ${error.message}`);
}