@ohos.data.distributedData (Distributed Data Management)

The distributed data management module implements collaboration between databases of different devices for applications. The APIs provided by distributed data management can be used to save data to distributed databases and perform operations such as adding, deleting, modifying, querying, and synchronizing data in distributed databases.

This module provides the following functions:

• KVManager: provides a KVManager instance to manage key-value (KV) stores.
• KvStoreResultSet⁸⁺: provides methods to obtain the KV store result set and query or move the data read position.
• Query⁸⁺: provides methods to query data from the database through a Query instance by using predicates.
• KVStore: provides methods to add data, delete data, and observe data changes and data synchronization through a KVStore instance.
• SingleKVStore: provides methods to query and synchronize data in a single KV store. This class inherits from KVStore, and data is not distinguished by device.
• DeviceKVStore⁸⁺: provides methods to query and synchronize data in a device KV store. This class inherits from KVStore, and data is distinguished by device.

NOTE

• The APIs provided by this module are no longer maintained since API version 9. You are advised to use @ohos.data.distributedKVStore.

• 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.

• All the APIs that need to obtain deviceId in this module are available only to system applications.

Modules to Import

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

distributedData.createKVManager

createKVManager(config: KVManagerConfig, callback: AsyncCallback<KVManager>): void

Creates a KVManager instance to manage KV stores. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Example

let kvManager;
try {
    const kvManagerConfig = {
        bundleName : 'com.example.datamanagertest',
        userInfo : {
            userId : '0',
            userType : distributedData.UserType.SAME_USER_ID
        }
    }
    distributedData.createKVManager(kvManagerConfig, function (err, manager) {
        if (err) {
            console.log("Failed to create KVManager: "  + JSON.stringify(err));
            return;
        }
        console.log("Created KVManager successfully");
        kvManager = manager;
    });
} catch (e) {
    console.log("An unexpected error occurred. Error:" + e);
}

distributedData.createKVManager

createKVManager(config: KVManagerConfig): Promise<KVManager>

Creates a KVManager instance to manage KV stores. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

try {
  const kvManagerConfig = {
    bundleName: 'com.example.datamanagertest',
    userInfo: {
      userId: '0',
      userType: distributedData.UserType.SAME_USER_ID
    }
  }
  distributedData.createKVManager(kvManagerConfig).then((manager) => {
    console.log("Created KVManager successfully");
    kvManager = manager;
  }).catch((err) => {
    console.error("Failed to create KVManager: " + JSON.stringify(err));
  });
} catch (e) {
  console.log("An unexpected error occurred. Error:" + e);
}

KVManagerConfig

Provides configuration of the KVManager object, including the bundle name and user information of the caller.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

UserInfo

Defines user information.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

UserType

Enumerates the user types.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

KVManager

Creates a KVManager object to obtain KV store information. Before calling any method in KVManager, you must use createKVManager to create a KVManager object.

getKVStore

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

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

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Example

let kvStore;
let kvManager;
try {
    const options = {
        createIfMissing : true,
        encrypt : false,
        backup : false,
        autoSync : true,
        kvStoreType : distributedData.KVStoreType.SINGLE_VERSION,
        securityLevel : distributedData.SecurityLevel.S2,
    };
    kvManager.getKVStore('storeId', options, function (err, store) {
        if (err) {
            console.log("getKVStore err: "  + JSON.stringify(err));
            return;
        }
        console.log("getKVStore success");
        kvStore = store;
    });
} catch (e) {
    console.log("An unexpected error occurred. Error:" + e);
}

getKVStore

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

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

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

let kvStore;
let kvManager;
try {
    const options = {
        createIfMissing : true,
        encrypt : false,
        backup : false,
        autoSync : true,
        kvStoreType : distributedData.KVStoreType.SINGLE_VERSION,
        securityLevel : distributedData.SecurityLevel.S2,
    };
    kvManager.getKVStore('storeId', options).then((store) => {
        console.log("getKVStore success");
        kvStore = store;
    }).catch((err) => {
        console.log("getKVStore err: "  + JSON.stringify(err));
    });
} catch (e) {
    console.log("An unexpected error occurred. Error:" + e);
}

closeKVStore⁸⁺

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

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

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Example

let kvStore;
let kvManager;
const options = {
    createIfMissing: true,
    encrypt: false,
    backup: false,
    autoSync: true,
    kvStoreType: distributedData.KVStoreType.SINGLE_VERSION,
    schema: undefined,
    securityLevel: distributedData.SecurityLevel.S2,
}
try {
    kvManager.getKVStore('storeId', options, async function (err, store) {
        console.log('getKVStore success');
        kvStore = store;
        kvManager.closeKVStore('appId', 'storeId', kvStore, function (err, data) {
            console.log('closeKVStore success');
        });
    });
} catch (e) {
    console.log('closeKVStore e ' + e);
}

closeKVStore⁸⁺

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

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

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

let kvManager;
let kvStore;
const options = {
    createIfMissing: true,
    encrypt: false,
    backup: false,
    autoSync: true,
    kvStoreType: distributedData.KVStoreType.SINGLE_VERSION,
    schema: undefined,
    securityLevel: distributedData.SecurityLevel.S2,
}
try {
    kvManager.getKVStore('storeId', options).then(async (store) => {
        console.log('getKVStore success');
        kvStore = store;
        kvManager.closeKVStore('appId', 'storeId', kvStore).then(() => {
            console.log('closeKVStore success');
        }).catch((err) => {
            console.log('closeKVStore err ' + JSON.stringify(err));
        });
    }).catch((err) => {
        console.log('CloseKVStore getKVStore err ' + JSON.stringify(err));
    });
} catch (e) {
    console.log('closeKVStore e ' + e);
}

deleteKVStore⁸⁺

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

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

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Example

let kvManager;
let kvStore;
const options = {
    createIfMissing : true,
    encrypt : false,
    backup : false,
    autoSync : true,
    kvStoreType : distributedData.KVStoreType.SINGLE_VERSION,
    schema : undefined,
    securityLevel : distributedData.SecurityLevel.S2,
}
try {
    kvManager.getKVStore('store', options, async function (err, store) {
        console.log('getKVStore success');
        kvStore = store;
        kvManager.deleteKVStore('appId', 'storeId', function (err, data) {
            console.log('deleteKVStore success');
        });
    });
} catch (e) {
    console.log('DeleteKVStore e ' + e);
}

deleteKVStore⁸⁺

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

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

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

let kvManager;
let kvStore;
const options = {
    createIfMissing : true,
    encrypt : false,
    backup : false,
    autoSync : true,
    kvStoreType : distributedData.KVStoreType.SINGLE_VERSION,
    schema : undefined,
    securityLevel : distributedData.SecurityLevel.S2,
}
try {
    kvManager.getKVStore('storeId', options).then(async (store) => {
        console.log('getKVStore success');
        kvStore = store;
        kvManager.deleteKVStore('appId', 'storeId').then(() => {
            console.log('deleteKVStore success');
        }).catch((err) => {
            console.log('deleteKVStore err ' + JSON.stringify(err));
        });
    }).catch((err) => {
        console.log('getKVStore err ' + JSON.stringify(err));
    });
} catch (e) {
    console.log('deleteKVStore e ' + e);
}

getAllKVStoreId⁸⁺

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

Obtains the IDs of all 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

let kvManager;
try {
    kvManager.getAllKVStoreId('appId', function (err, data) {
        console.log('GetAllKVStoreId success');
        console.log('GetAllKVStoreId size = ' + data.length);
    });
} catch (e) {
    console.log('GetAllKVStoreId e ' + e);
}

getAllKVStoreId⁸⁺

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

Obtains the IDs of all 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

let kvManager;
try {
    console.log('GetAllKVStoreId');
    kvManager.getAllKVStoreId('appId').then((data) => {
        console.log('getAllKVStoreId success');
        console.log('size = ' + data.length);
    }).catch((err) => {
        console.log('getAllKVStoreId err ' + JSON.stringify(err));
    });
} catch(e) {
    console.log('getAllKVStoreId e ' + e);
}

on('distributedDataServiceDie')⁸⁺

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

Subscribes to service status changes.

System capability: SystemCapability.DistributedDataManager.KVStore.DistributedKVStore

Parameters

Example

let kvManager;
try {
    console.log('KVManagerOn');
    const deathCallback = function () {
        console.log('death callback call');
    }
    kvManager.on('distributedDataServiceDie', deathCallback);
} catch (e) {
    console.log("An unexpected error occurred. Error:" + e);
}

off('distributedDataServiceDie')⁸⁺

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

Unsubscribes from service status changes.

System capability: SystemCapability.DistributedDataManager.KVStore.DistributedKVStore

Parameters

Example

let kvManager;
try {
    console.log('KVManagerOff');
    const deathCallback = function () {
        console.log('death callback call');
    }
    kvManager.off('distributedDataServiceDie', deathCallback);
} catch (e) {
    console.log("An unexpected error occurred. Error:" + e);
}
    

Options

Provides KV store configuration.

KVStoreType

Enumerates the KV store types.

SecurityLevel

Enumerates the KV store security levels.

Constants

Defines the KV store constants.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Schema⁸⁺

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

constructor⁸⁺

constructor()

A constructor used to create a Schema instance.

System capability: SystemCapability.DistributedDataManager.KVStore.DistributedKVStore

FieldNode⁸⁺

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

System capability: SystemCapability.DistributedDataManager.KVStore.DistributedKVStore

constructor⁸⁺

constructor(name: string)

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

System capability: SystemCapability.DistributedDataManager.KVStore.DistributedKVStore

Parameters

appendChild⁸⁺

appendChild(child: FieldNode): boolean

Appends a child node to this FieldNode.

System capability: SystemCapability.DistributedDataManager.KVStore.DistributedKVStore

Parameters

Return value

Example

import ddm from '@ohos.data.distributedData';
try {
    let node = new ddm.FieldNode("root");
    let child1 = new ddm.FieldNode("child1");
    let child2 = new ddm.FieldNode("child2");
    let child3 = new ddm.FieldNode("child3");
    node.appendChild(child1);
    node.appendChild(child2);
    node.appendChild(child3);
    console.log("appendNode " + JSON.stringify(node));
    child1 = null;
    child2 = null;
    child3 = null;
    node = null;
} catch (e) {
    console.log("AppendChild " + e);
}

KvStoreResultSet⁸⁺

Provides methods to obtain the KV store result sets, and query and move the data read position.

Before calling any method in KvStoreResultSet, you must use getKVStore to obtain a KVStore object.

getCount⁸⁺

getCount(): number

Obtains the total number of rows in the result set.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

let kvStore;
try {
    let resultSet;
    kvStore.getResultSet('batch_test_string_key').then((result) => {
        console.log('getResultSet succeed.');
        resultSet = result;
    }).catch((err) => {
        console.log('getResultSet failed: ' + err);
    });
    const count = resultSet.getCount();
    console.log("getCount succeed:" + count);
} catch (e) {
    console.log("getCount failed: " + e);
}

getPosition⁸⁺

getPosition(): number

Obtains the current data read position (position from which data is read) in the result set.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

let kvStore;
try {
    let resultSet;
    kvStore.getResultSet('batch_test_string_key').then((result) => {
        console.log('getResultSet succeeded.');
        resultSet = result;
    }).catch((err) => {
        console.log('getResultSet failed: ' + err);
    });
    const position = resultSet.getPosition();
    console.log("getPosition succeed:" + position);
} catch (e) {
    console.log("getPosition failed: " + e);
}

moveToFirst⁸⁺

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

let kvStore;
try {
    let resultSet;
    kvStore.getResultSet('batch_test_string_key').then((result) => {
        console.log('getResultSet succeed.');
        resultSet = result;
    }).catch((err) => {
        console.log('getResultSet failed: ' + err);
    });
    const moved1 = resultSet.moveToFirst();
    console.log("moveToFirst succeed: " + moved1);
} catch (e) {
    console.log("moveToFirst failed " + e);
}

moveToLast⁸⁺

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

let kvStore;
try {
    let resultSet;
    kvStore.getResultSet('batch_test_string_key').then((result) => {
        console.log('getResultSet succeed.');
        resultSet = result;
    }).catch((err) => {
        console.log('getResultSet failed: ' + err);
    });
    const moved2 = resultSet.moveToLast();
    console.log("moveToLast succeed:" + moved2);
} catch (e) {
    console.log("moveToLast failed: " + e);
}

moveToNext⁸⁺

moveToNext(): boolean

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

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

let kvStore;
try {
    let resultSet;
    kvStore.getResultSet('batch_test_string_key').then((result) => {
        console.log('getResultSet succeed.');
        resultSet = result;
    }).catch((err) => {
        console.log('getResultSet failed: ' + err);
    });
    const moved3 = resultSet.moveToNext();
    console.log("moveToNext succeed: " + moved3);
} catch (e) {
    console.log("moveToNext failed: " + e);
}

moveToPrevious⁸⁺

moveToPrevious(): boolean

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

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

let kvStore;
try {
    let resultSet;
    kvStore.getResultSet('batch_test_string_key').then((result) => {
        console.log('getResultSet succeed.');
        resultSet = result;
    }).catch((err) => {
        console.log('getResultSet failed: ' + err);
    });
    const moved4 = resultSet.moveToPrevious();
    console.log("moveToPrevious succeed:" + moved4);
} catch (e) {
    console.log("moveToPrevious failed: " + e);
}

move⁸⁺

move(offset: number): boolean

Moves the data read position with the specified offset from the current position.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

let kvStore;
try {
    let resultSet;
    kvStore.getResultSet('batch_test_string_key').then((result) => {
        console.log('getResultSet succeed.');
        resultSet = result;
    }).catch((err) => {
        console.log('getResultSet failed: ' + err);
    });
    const moved5 = resultSet.move(1);
    console.log("move succeed:" + moved5);
} catch (e) {
    console.log("move failed: " + e);
}

moveToPosition⁸⁺

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

let kvStore;
try {
    let resultSet;
    kvStore.getResultSet('batch_test_string_key').then((result) => {
        console.log('getResultSet succeed.');
        resultSet = result;
    }).catch((err) => {
        console.log('getResultSet failed: ' + err);
    });
    const moved6 = resultSet.moveToPosition(1);
    console.log("moveToPosition succeed: " + moved6);
} catch (e) {
    console.log("moveToPosition failed: " + e);
}

isFirst⁸⁺

isFirst(): boolean

Checks whether the data read position is the first row.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

let kvStore;
try {
    let resultSet;
    kvStore.getResultSet('batch_test_string_key').then((result) => {
        console.log('getResultSet succeed.');
        resultSet = result;
    }).catch((err) => {
        console.log('getResultSet failed: ' + err);
    });
    const isfirst = resultSet.isFirst();
    console.log("Check isFirst succeed:" + isfirst);
} catch (e) {
    console.log("Check isFirst failed: " + e);
}

isLast⁸⁺

isLast(): boolean

Checks whether the data read position is the last row.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

let kvStore;
try {
    let resultSet;
    kvStore.getResultSet('batch_test_string_key').then((result) => {
        console.log('getResultSet succeed.');
        resultSet = result;
    }).catch((err) => {
        console.log('getResultSet failed: ' + err);
    });
    const islast = resultSet.isLast();
    console.log("Check isLast succeed: " + islast);
} catch (e) {
    console.log("Check isLast failed: " + e);
}

isBeforeFirst⁸⁺

isBeforeFirst(): boolean

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

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

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

isAfterLast⁸⁺

isAfterLast(): boolean

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

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

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

getEntry⁸⁺

getEntry(): Entry

Obtains the KV pair from the current position.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

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

Query⁸⁺

Provides methods to create a Query object, which defines different data query criteria.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

constructor⁸⁺

constructor()

A constructor used to create a Schema instance.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

reset⁸⁺

reset(): Query

Resets the Query object.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

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

equalTo⁸⁺

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

try {
    let query = new distributedData.Query();
    query.equalTo("field", "value");
    console.log("query is " + query.getSqlLike());
    query = null;
} catch (e) {
    console.log("duplicated calls should be ok :" + e);
}

notEqualTo⁸⁺

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

try {
    let query = new distributedData.Query();
    query.notEqualTo("field", "value");
    console.log("query is " + query.getSqlLike());
    query = null;
} catch (e) {
    console.log("duplicated calls should be ok :" + e);
}

greaterThan⁸⁺

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

try {
    let query = new distributedData.Query();
    query.greaterThan("field", "value");
    console.log("query is " + query.getSqlLike());
    query = null;
} catch (e) {
    console.log("duplicated calls should be ok :" + e);
}

lessThan⁸⁺

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

try {
    let query = new distributedData.Query();
    query.lessThan("field", "value");
    console.log("query is " + query.getSqlLike());
    query = null;
} catch (e) {
    console.log("duplicated calls should be ok :" + e);
}

greaterThanOrEqualTo⁸⁺

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

try {
    let query = new distributedData.Query();
    query.greaterThanOrEqualTo("field", "value");
    console.log("query is " + query.getSqlLike());
    query = null;
} catch (e) {
    console.log("duplicated calls should be ok :" + e);
}

lessThanOrEqualTo⁸⁺

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

try {
    let query = new distributedData.Query();
    query.lessThanOrEqualTo("field", "value");
    console.log("query is " + query.getSqlLike());
    query = null;
} catch (e) {
    console.log("duplicated calls should be ok :" + e);
}

isNull⁸⁺

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

try {
    let query = new distributedData.Query();
    query.isNull("field");
    console.log("query is " + query.getSqlLike());
    query = null;
} catch (e) {
    console.log("duplicated calls should be ok :" + e);
}

inNumber⁸⁺

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

try {
    let query = new distributedData.Query();
    query.inNumber("field", [0, 1]);
    console.log("query is " + query.getSqlLike());
    query = null;
} catch (e) {
    console.log("duplicated calls should be ok :" + e);
}

inString⁸⁺

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

try {
    let query = new distributedData.Query();
    query.inString("field", ['test1', 'test2']);
    console.log("query is " + query.getSqlLike());
    query = null;
} catch (e) {
    console.log("duplicated calls should be ok :" + e);
}

notInNumber⁸⁺

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

try {
    let query = new distributedData.Query();
    query.notInNumber("field", [0, 1]);
    console.log("query is " + query.getSqlLike());
    query = null;
} catch (e) {
    console.log("duplicated calls should be ok :" + e);
}

notInString⁸⁺

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

try {
    let query = new distributedData.Query();
    query.notInString("field", ['test1', 'test2']);
    console.log("query is " + query.getSqlLike());
    query = null;
} catch (e) {
    console.log("duplicated calls should be ok :" + e);
}

like⁸⁺

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

try {
    let query = new distributedData.Query();
    query.like("field", "value");
    console.log("query is " + query.getSqlLike());
    query = null;
} catch (e) {
    console.log("duplicated calls should be ok :" + e);
}

unlike⁸⁺

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

try {
    let query = new distributedData.Query();
    query.unlike("field", "value");
    console.log("query is " + query.getSqlLike());
    query = null;
} catch (e) {
    console.log("duplicated calls should be ok :" + e);
}

and⁸⁺

and(): Query

Creates a Query object with the AND condition.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

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

or⁸⁺

or(): Query

Creates a Query object with the OR condition.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

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

orderByAsc⁸⁺

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

try {
    let query = new distributedData.Query();
    query.notEqualTo("field", "value");
    query.orderByAsc("field");
    console.log("query is " + query.getSqlLike());
    query = null;
} catch (e) {
    console.log("duplicated calls should be ok :" + e);
}

orderByDesc⁸⁺

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

try {
    let query = new distributedData.Query();
    query.notEqualTo("field", "value");
    query.orderByDesc("field");
    console.log("query is " + query.getSqlLike());
    query = null;
} catch (e) {
    console.log("duplicated calls should be ok :" + e);
}

limit⁸⁺

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

Creates a Query object to specify the number of results and where to start.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

let total = 10;
let offset = 1;
try {
    let query = new distributedData.Query();
    query.notEqualTo("field", "value");
    query.limit(total, offset);
    console.log("query is " + query.getSqlLike());
    query = null;
} catch (e) {
    console.log("duplicated calls should be ok :" + e);
}

isNotNull⁸⁺

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

try {
    let query = new distributedData.Query();
    query.isNotNull("field");
    console.log("query is " + query.getSqlLike());
    query = null;
} catch (e) {
    console.log("duplicated calls should be ok :" + e);
}

beginGroup⁸⁺

beginGroup(): Query

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

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

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

endGroup⁸⁺

endGroup(): Query

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

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

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

prefixKey⁸⁺

prefixKey(prefix: string): Query

Creates a Query object with a specified key prefix.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

try {
    let query = new distributedData.Query();
    query.prefixKey("$.name");
    query.prefixKey("0");
    console.log("query is " + query.getSqlLike());
    query = null;
} catch (e) {
    console.log("duplicated calls should be ok :" + e);
}

setSuggestIndex⁸⁺

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

try {
    let query = new distributedData.Query();
    query.setSuggestIndex("$.name");
    query.setSuggestIndex("0");
    console.log("query is " + query.getSqlLike());
    query = null;
} catch (e) {
   console.log("duplicated calls should be ok :" + e);
}

deviceId⁸⁺

deviceId(deviceId:string):Query

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

NOTE

deviceId is obtained by deviceManager.getTrustedDeviceListSync. The APIs of the deviceManager module are system interfaces and available only to system applications. For details about how to obtain deviceId, see sync().

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

try {
    let query = new distributedData.Query();
    query.deviceId("deviceId");
    console.log("query is " + query.getSqlLike());
} catch (e) {
    console.log("should be ok on Method Chaining : " + e);
}

getSqlLike⁸⁺

getSqlLike():string

Obtains the query statement of the Query object.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

try {
    let query = new distributedData.Query();
    let sql1 = query.getSqlLike();
    console.log("GetSqlLike sql=" + sql1);
} catch (e) {
    console.log("duplicated calls should be ok : " + e);
}

KVStore

Provides methods to manage data in a KV store, for example, adding or deleting data and subscribing to data changes or completion of data synchronization.

Before calling any method in KVStore, you must use getKVStore to obtain a KVStore object.

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

Example

let kvStore;
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, function (err,data) {
        if (err != undefined) {
            console.log("put err: " + JSON.stringify(err));
            return;
        }
        console.log("put success");
    });
}catch (e) {
    console.log("An unexpected error occurred. Error:" + e);
}

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

Example

let kvStore;
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((data) => {
        console.log("put success: " + JSON.stringify(data));
    }).catch((err) => {
        console.log("put err: " + JSON.stringify(err));
    });
}catch (e) {
    console.log("An unexpected error occurred. Error:" + e);
}

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

Example

let kvStore;
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, function (err,data) {
        if (err != undefined) {
            console.log("put err: " + JSON.stringify(err));
            return;
        }
        console.log("put success");
        kvStore.delete(KEY_TEST_STRING_ELEMENT, function (err,data) {
            if (err != undefined) {
                console.log("delete err: " + JSON.stringify(err));
                return;
            }
            console.log("delete success");
        });
    });
}catch (e) {
    console.log("An unexpected error occurred. Error:" + e);
}

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

Example

let kvStore;
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((data) => {
        console.log("put success: " + JSON.stringify(data));
        kvStore.delete(KEY_TEST_STRING_ELEMENT).then((data) => {
            console.log("delete success");
        }).catch((err) => {
            console.log("delete err: " + JSON.stringify(err));
        });
    }).catch((err) => {
        console.log("put err: " + JSON.stringify(err));
    });
}catch (e) {
    console.log("An unexpected error occurred. Error:" + e);
}

on('dataChange')

on(event: 'dataChange', type: SubscribeType, listener: Callback<ChangeNotification>): void

Subscribes to data changes of the specified type.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Example

let kvStore;
kvStore.on('dataChange', distributedData.SubscribeType.SUBSCRIBE_TYPE_LOCAL, function (data) {
    console.log("dataChange callback call data: " + JSON.stringify(data));
});

on('syncComplete')

on(event: 'syncComplete', syncCallback: Callback<Array<[string, number]>>): void

Subscribes to synchronization complete events.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Example

let kvStore;
kvStore.on('syncComplete', function (data) {
    console.log("callback call data: " + data);
});

off('dataChange')⁸⁺

off(event:'dataChange', listener?: Callback<ChangeNotification>): void

Unsubscribes from data changes.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Example

let kvStore;
class KvstoreModel {
    call(data) {
        console.log("dataChange: " + data);
    }
    subscribeDataChange() {
        if (kvStore != null) {
            kvStore.on('dataChange', distributedData.SubscribeType.SUBSCRIBE_TYPE_REMOTE, this.call);
        }
    }
    unsubscribeDataChange() {
        if (kvStore != null) {
            kvStore.off('dataChange', this.call);
        }
    }
}

off('syncComplete')⁸⁺

off(event: 'syncComplete', syncCallback?: Callback<Array<[string, number]>>): void

Unsubscribes from synchronization complete events.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Example

let kvStore;
class KvstoreModel {
    call(data) {
        console.log("syncComplete: " + data);
    }
    subscribeSyncComplete() {
        if (kvStore != null) {
            kvStore.on('syncComplete', this.call);
        }
    }
    unsubscribeSyncComplete() {
        if (kvStore != null) {
            kvStore.off('syncComplete', this.call);
        }
    }
}

putBatch⁸⁺

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

Inserts KV pairs in batches to this KV store. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Example

let kvStore;
try {
    let entries = [];
    for (var i = 0; i < 10; i++) {
        var key = 'batch_test_string_key';
        var entry = {
            key : key + i,
            value : {
                type : distributedData.ValueType.STRING,
                value : 'batch_test_string_value'
            }
        }
        entries.push(entry);
    }
    console.log('entries: ' + JSON.stringify(entries));
    kvStore.putBatch(entries, async function (err,data) {
        console.log('putBatch success');
        kvStore.getEntries('batch_test_string_key', function (err,entries) {
            console.log('getEntries success');
            console.log('entries.length: ' + entries.length);
            console.log('entries[0]: ' + JSON.stringify(entries[0]));
        });
    });
}catch(e) {
    console.log('PutBatch e ' + JSON.stringify(e));
}

putBatch⁸⁺

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

Inserts KV pairs in batches to this KV store. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

let kvStore;
try {
    let entries = [];
    for (var i = 0; i < 10; i++) {
        var key = 'batch_test_string_key';
        var entry = {
            key : key + i,
            value : {
                type : distributedData.ValueType.STRING,
                value : 'batch_test_string_value'
            }
        }
        entries.push(entry);
    }
    console.log('entries: ' + JSON.stringify(entries));
    kvStore.putBatch(entries).then(async (err) => {
        console.log('putBatch success');
        kvStore.getEntries('batch_test_string_key').then((entries) => {
            console.log('getEntries success');
            console.log('PutBatch ' + JSON.stringify(entries));
        }).catch((err) => {
            console.log('getEntries fail ' + JSON.stringify(err));
        });
    }).catch((err) => {
        console.log('putBatch fail ' + JSON.stringify(err));
    });
}catch(e) {
    console.log('PutBatch e ' + JSON.stringify(e));
}

deleteBatch⁸⁺

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

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

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Example

let kvStore;
try {
    let entries = [];
    let keys = [];
    for (var i = 0; i < 5; i++) {
        var key = 'batch_test_string_key';
        var entry = {
            key : key + i,
            value : {
                type : distributedData.ValueType.STRING,
                value : 'batch_test_string_value'
            }
        }
        entries.push(entry);
        keys.push(key + i);
    }
    console.log('entries: ' + JSON.stringify(entries));
    kvStore.putBatch(entries, async function (err,data) {
        console.log('putBatch success');
        kvStore.deleteBatch(keys, async function (err,data) {
            console.log('deleteBatch success');
        });
    });
}catch(e) {
    console.log('DeleteBatch e ' + e);
}

deleteBatch⁸⁺

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

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

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

let kvStore;
try {
    let entries = [];
    let keys = [];
    for (var i = 0; i < 5; i++) {
        var key = 'batch_test_string_key';
        var entry = {
            key : key + i,
            value : {
                type : distributedData.ValueType.STRING,
                value : 'batch_test_string_value'
            }
        }
        entries.push(entry);
        keys.push(key + i);
    }
    console.log('entries: ' + JSON.stringify(entries));
    kvStore.putBatch(entries).then(async (err) => {
        console.log('putBatch success');
        kvStore.deleteBatch(keys).then((err) => {
            console.log('deleteBatch success');
        }).catch((err) => {
            console.log('deleteBatch fail ' + JSON.stringify(err));
        });
    }).catch((err) => {
        console.log('putBatch fail ' + JSON.stringify(err));
    });
}catch(e) {
    console.log('DeleteBatch e ' + e);
}

startTransaction⁸⁺

startTransaction(callback: AsyncCallback<void>): void

Starts the transaction in this KV store. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Example

let kvStore;
function putBatchString(len, prefix) {
    let entries = [];
    for (var i = 0; i < len; i++) {
        var entry = {
            key : prefix + i,
            value : {
                type : distributedData.ValueType.STRING,
                value : 'batch_test_string_value'
            }
        }
        entries.push(entry);
    }
    return entries;
}
try {
    var count = 0;
    kvStore.on('dataChange', 0, function (data) {
        console.log('startTransaction 0' + data)
        count++;
    });
    kvStore.startTransaction(async function (err,data) {
        console.log('startTransaction success');
        let entries = putBatchString(10, 'batch_test_string_key');
        console.log('entries: ' + JSON.stringify(entries));
        kvStore.putBatch(entries, async function (err,data) {
            console.log('putBatch success');
        });
    });
}catch(e) {
    console.log('startTransaction e ' + e);
}

startTransaction⁸⁺

startTransaction(): Promise<void>

Starts the transaction in this KV store. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

let kvStore;
try {
    var count = 0;
    kvStore.on('dataChange', distributedData.SubscribeType.SUBSCRIBE_TYPE_ALL, function (data) {
        console.log('startTransaction ' + JSON.stringify(data));
        count++;
    });
    kvStore.startTransaction().then(async (err) => {
        console.log('startTransaction success');
    }).catch((err) => {
        console.log('startTransaction fail ' + JSON.stringify(err));
    });
}catch(e) {
    console.log('startTransaction e ' + e);
}

commit⁸⁺

commit(callback: AsyncCallback<void>): void

Commits the transaction in this KV store. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Example

let kvStore;
try {
    kvStore.commit(function (err,data) {
        if (err == undefined) {
            console.log('commit success');
        } else {
            console.log('commit fail');
        }
    });
}catch(e) {
    console.log('Commit e ' + e);
}

commit⁸⁺

commit(): Promise<void>

Commits the transaction in this KV store. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

let kvStore;
try {
    kvStore.commit().then(async (err) => {
        console.log('commit success');
    }).catch((err) => {
        console.log('commit fail ' + JSON.stringify(err));
    });
}catch(e) {
    console.log('Commit e ' + e);
}

rollback⁸⁺

rollback(callback: AsyncCallback<void>): void

Rolls back the transaction in this KV store. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Example

let kvStore;
try {
    kvStore.rollback(function (err,data) {
        if (err == undefined) {
            console.log('commit success');
        } else {
            console.log('commit fail');
        }
    });
}catch(e) {
    console.log('Rollback e ' + e);
}

rollback⁸⁺

rollback(): Promise<void>

Rolls back the transaction in this KV store. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

let kvStore;
try {
    kvStore.rollback().then(async (err) => {
        console.log('rollback success');
    }).catch((err) => {
        console.log('rollback fail ' + JSON.stringify(err));
    });
}catch(e) {
    console.log('Rollback e ' + e);
}

enableSync⁸⁺

enableSync(enabled: boolean, callback: AsyncCallback<void>): void

Sets data synchronization, which can be enabled or disabled. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Example

let kvStore;
try {
    kvStore.enableSync(true, function (err,data) {
        if (err == undefined) {
            console.log('enableSync success');
        } else {
            console.log('enableSync fail');
        }
    });
}catch(e) {
    console.log('EnableSync e ' + e);
}

enableSync⁸⁺

enableSync(enabled: boolean): Promise<void>

Sets data synchronization, which can be enabled or disabled. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

let kvStore;
try {
    kvStore.enableSync(true).then((err) => {
        console.log('enableSync success');
    }).catch((err) => {
        console.log('enableSync fail ' + JSON.stringify(err));
    });
}catch(e) {
    console.log('EnableSync e ' + e);
}

setSyncRange⁸⁺

setSyncRange(localLabels: string[], remoteSupportLabels: string[], callback: AsyncCallback<void>): void

Sets the data synchronization range. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Example

let kvStore;
try {
    const localLabels = ['A', 'B'];
    const remoteSupportLabels = ['C', 'D'];
    kvStore.setSyncRange(localLabels, remoteSupportLabels, function (err,data) {
        console.log('SetSyncRange put success');
    });
}catch(e) {
    console.log('SetSyncRange e ' + e);
}

setSyncRange⁸⁺

setSyncRange(localLabels: string[], remoteSupportLabels: string[]): Promise<void>

Sets the data synchronization range. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

let kvStore;
try {
    const localLabels = ['A', 'B'];
    const remoteSupportLabels = ['C', 'D'];
    kvStore.setSyncRange(localLabels, remoteSupportLabels).then((err) => {
        console.log('setSyncRange success');
    }).catch((err) => {
        console.log('delete fail ' + err);
    });
}catch(e) {
    console.log('SetSyncRange e ' + e);
}

SubscribeType

Enumerates the subscription types.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

ChangeNotification

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

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Entry

Defines the KV pairs stored in the KV store.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Value

Defines the value object in a KV store.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

ValueType

Enumerates the data types.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

SingleKVStore

Provides methods to query and synchronize data in a single KV store. This class inherits from KVStore.

Data is not distinguished by device in a single KV store. The data written to different devices using the same key will be overwritten. For example, a single KV store can be used to synchronize a user's calendar and contact data between different devices.

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

get

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

Example

let kvStore;
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, function (err,data) {
        if (err != undefined) {
            console.log("put err: " + JSON.stringify(err));
            return;
        }
        console.log("put success");
        kvStore.get(KEY_TEST_STRING_ELEMENT, function (err,data) {
            console.log("get success data: " + data);
        });
    });
}catch (e) {
    console.log("An unexpected error occurred. Error:" + e);
}

get

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

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

Example

let kvStore;
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((data) => {
        console.log("put success: " + JSON.stringify(data));
        kvStore.get(KEY_TEST_STRING_ELEMENT).then((data) => {
            console.log("get success data: " + data);
        }).catch((err) => {
            console.log("get err: " + JSON.stringify(err));
        });
    }).catch((err) => {
        console.log("put err: " + JSON.stringify(err));
    });
}catch (e) {
    console.log("An unexpected error occurred. Error:" + e);
}

getEntries⁸⁺

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

Example

let kvStore;
try {
    let entries = [];
    for (var i = 0; i < 10; i++) {
        var key = 'batch_test_number_key';
        var entry = {
            key : key + i,
            value : {
                type : distributedData.ValueType.INTEGER,
                value : 222
            }
        }
        entries.push(entry);
    }
    kvStore.putBatch(entries, async function (err,data) {
        console.log('putBatch success');
        kvStore.getEntries('batch_test_number_key', function (err,entries) {
            console.log('getEntries success');
            console.log('entries.length: ' + entries.length);
            console.log('entries[0]: ' + JSON.stringify(entries[0]));
        });
    });
}catch(e) {
    console.log('PutBatch e ' + e);
}

getEntries⁸⁺

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

Example

let kvStore;
try {
    let entries = [];
    for (var i = 0; i < 10; i++) {
        var key = 'batch_test_string_key';
        var entry = {
            key : key + i,
            value : {
                type : distributedData.ValueType.STRING,
                value : 'batch_test_string_value'
            }
        }
        entries.push(entry);
    }
    console.log('entries: ' + entries);
    kvStore.putBatch(entries).then(async (err) => {
        console.log('putBatch success');
        kvStore.getEntries('batch_test_string_key').then((entries) => {
            console.log('getEntries success');
            console.log('entries.length: ' + entries.length);
            console.log('entries[0]: ' + JSON.stringify(entries[0]));
            console.log('entries[0].value: ' + JSON.stringify(entries[0].value));
            console.log('entries[0].value.value: ' + entries[0].value.value);
        }).catch((err) => {
            console.log('getEntries fail ' + JSON.stringify(err));
        });
    }).catch((err) => {
        console.log('putBatch fail ' + JSON.stringify(err));
    });
}catch(e) {
    console.log('PutBatch e ' + e);
}

getEntries⁸⁺

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

Example

let kvStore;
try {
    var arr = new Uint8Array([21,31]);
    let entries = [];
    for (var i = 0; i < 10; i++) {
        var key = 'batch_test_bool_key';
        var entry = {
            key : key + i,
            value : {
                type : distributedData.ValueType.BYTE_ARRAY,
                value : arr
            }
        }
        entries.push(entry);
    }
    console.log('entries: ' + JSON.stringify(entries));
    kvStore.putBatch(entries, async function (err,data) {
        console.log('putBatch success');
        const query = new distributedData.Query();
        query.prefixKey("batch_test");
        kvStore.getEntries(query, function (err,entries) {
            console.log('getEntries success');
            console.log('entries.length: ' + entries.length);
            console.log('entries[0]: ' + JSON.stringify(entries[0]));
        });
    });
    console.log('GetEntries success');
}catch(e) {
    console.log('GetEntries e ' + e);
}

getEntries⁸⁺

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

Example

let kvStore;
try {
    var arr = new Uint8Array([21,31]);
    let entries = [];
    for (var i = 0; i < 10; i++) {
        var key = 'batch_test_bool_key';
        var entry = {
            key : key + i,
            value : {
                type : distributedData.ValueType.BYTE_ARRAY,
                value : arr
            }
        }
        entries.push(entry);
    }
    console.log('entries: ' + JSON.stringify(entries));
    kvStore.putBatch(entries).then(async (err) => {
        console.log('putBatch success');
        const query = new distributedData.Query();
        query.prefixKey("batch_test");
        kvStore.getEntries(query).then((entries) => {
            console.log('getEntries success');
        }).catch((err) => {
            console.log('getEntries fail ' + JSON.stringify(err));
        });
    }).catch((err) => {
        console.log('GetEntries putBatch fail ' + JSON.stringify(err))
    });
    console.log('GetEntries success');
}catch(e) {
    console.log('GetEntries e ' + e);
}

getResultSet⁸⁺

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

Obtains the result set with the specified prefix. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Example

let kvStore;
try {
    let resultSet;
    let entries = [];
    for (var i = 0; i < 10; i++) {
        var key = 'batch_test_string_key';
        var entry = {
            key : key + i,
            value : {
                type : distributedData.ValueType.STRING,
                value : 'batch_test_string_value'
            }
        }
        entries.push(entry);
    }
    kvStore.putBatch(entries, async function (err, data) {
        console.log('GetResultSet putBatch success');
        kvStore.getResultSet('batch_test_string_key', async function (err, result) {
            console.log('GetResultSet getResultSet succeed.');
            resultSet = result;
            kvStore.closeResultSet(resultSet, function (err, data) {
                console.log('GetResultSet closeResultSet success');
            })
        });
    });
}catch(e) {
    console.log('GetResultSet e ' + e);
}

getResultSet⁸⁺

getResultSet(keyPrefix: string): Promise<KvStoreResultSet>

Obtains the result set with the specified prefix. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

let kvStore;
try {
    let resultSet;
    let entries = [];
    for (var i = 0; i < 10; i++) {
        var key = 'batch_test_string_key';
        var entry = {
            key : key + i,
            value : {
                type : distributedData.ValueType.STRING,
                value : 'batch_test_string_value'
            }
        }
        entries.push(entry);
    }
    kvStore.putBatch(entries).then(async (err) => {
        console.log('putBatch success');
    }).catch((err) => {
        console.log('PutBatch putBatch fail ' + JSON.stringify(err));
    });
    kvStore.getResultSet('batch_test_string_key').then((result) => {
        console.log('GetResult getResultSet succeed.');
        resultSet = result;
    }).catch((err) => {
        console.log('getResultSet failed: ' + JSON.stringify(err));
    });
    kvStore.closeResultSet(resultSet).then((err) => {
        console.log('GetResult closeResultSet success');
    }).catch((err) => {
        console.log('closeResultSet fail ' + JSON.stringify(err));
    });
}catch(e) {
    console.log('GetResult e ' + e);
}

getResultSet⁸⁺

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

Example

let kvStore;
try {
    let resultSet;
    let entries = [];
    for (var i = 0; i < 10; i++) {
        var key = 'batch_test_string_key';
        var entry = {
            key : key + i,
            value : {
                type : distributedData.ValueType.STRING,
                value : 'batch_test_string_value'
            }
        }
        entries.push(entry);
    }
    kvStore.putBatch(entries, async function (err, data) {
        console.log('putBatch success');
        const query = new distributedData.Query();
        query.prefixKey("batch_test");
        kvStore.getResultSet(query, async function (err, result) {
            console.log('getResultSet succeed.');
            resultSet = result;
        });
    });
} catch(e) {
    console.log('GetResultSet e ' + e);
}

getResultSet⁸⁺

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

Example

let kvStore;
try {
    let resultSet;
    let entries = [];
    for (var i = 0; i < 10; i++) {
        var key = 'batch_test_string_key';
        var entry = {
            key : key + i,
            value : {
                type : distributedData.ValueType.STRING,
                value : 'batch_test_string_value'
            }
        }
        entries.push(entry);
    }
    kvStore.putBatch(entries).then(async (err) => {
        console.log('putBatch success');
    }).catch((err) => {
        console.log('putBatch fail ' + JSON.stringify(err));
    });
    const query = new distributedData.Query();
    query.prefixKey("batch_test");
    kvStore.getResultSet(query).then((result) => {
        console.log(' getResultSet succeed.');
        resultSet = result;
    }).catch((err) => {
        console.log('getResultSet failed: ' + JSON.stringify(err));
    });
}catch(e) {
    console.log('GetResultSet e ' + e);
}

closeResultSet⁸⁺

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

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

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Example

let kvStore;
try {
    let resultSet = null;
    kvStore.closeResultSet(resultSet, function (err, data) {
        if (err == undefined) {
            console.log('closeResultSet success');
        } else {
            console.log('closeResultSet fail');
        }
    });
}catch(e) {
    console.log('CloseResultSet e ' + e);
}

closeResultSet⁸⁺

closeResultSet(resultSet: KvStoreResultSet): Promise<void>

Closes the KvStoreResultSet object obtained by SingleKvStore.getResultSet. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

let kvStore;
try {
    let resultSet = null;
    kvStore.closeResultSet(resultSet).then(() => {
        console.log('closeResultSet success');
    }).catch((err) => {
        console.log('closeResultSet fail ' + JSON.stringify(err));
    });
}catch(e) {
    console.log('CloseResultSet e ' + e);
}

getResultSize⁸⁺

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

Example

let kvStore;
try {
    let entries = [];
    for (var i = 0; i < 10; i++) {
        var key = 'batch_test_string_key';
        var entry = {
            key : key + i,
            value : {
                type : distributedData.ValueType.STRING,
                value : 'batch_test_string_value'
            }
        }
        entries.push(entry);
    }
    kvStore.putBatch(entries, async function (err, data) {
        console.log('putBatch success');
        const query = new distributedData.Query();
        query.prefixKey("batch_test");
        kvStore.getResultSize(query, async function (err, resultSize) {
            console.log('getResultSet succeed.');
        });
    });
} catch(e) {
    console.log('GetResultSize e ' + e);
}

getResultSize⁸⁺

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

Example

let kvStore;
try {
    let entries = [];
    for (var i = 0; i < 10; i++) {
        var key = 'batch_test_string_key';
        var entry = {
            key : key + i,
            value : {
                type : distributedData.ValueType.STRING,
                value : 'batch_test_string_value'
            }
        }
        entries.push(entry);
    }
    kvStore.putBatch(entries).then(async (err) => {
        console.log('putBatch success');
    }).catch((err) => {
        console.log('putBatch fail ' + JSON.stringify(err));
    });
    const query = new distributedData.Query();
    query.prefixKey("batch_test");
    kvStore.getResultSize(query).then((resultSize) => {
        console.log('getResultSet succeed.');
    }).catch((err) => {
        console.log('getResultSet failed: ' + JSON.stringify(err));
    });
}catch(e) {
    console.log('GetResultSize e ' + e);
}

removeDeviceData⁸⁺

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

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

NOTE

deviceId is obtained by deviceManager.getTrustedDeviceListSync. The APIs of the deviceManager module are system interfaces and available only to system applications. For details about how to obtain deviceId, see sync().

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Example

let kvStore;
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 function (err,data) {
        console.log('put success');
        const deviceid = 'no_exist_device_id';
        kvStore.removeDeviceData(deviceid, async function (err,data) {
            if (err == undefined) {
                console.log('removeDeviceData success');
            } else {
                console.log('removeDeviceData fail');
                kvStore.get(KEY_TEST_STRING_ELEMENT, async function (err,data) {
                    console.log('RemoveDeviceData get success');
                });
            }
        });
    });
}catch(e) {
    console.log('RemoveDeviceData e ' + e);
}

removeDeviceData⁸⁺

removeDeviceData(deviceId: string): Promise<void>

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

NOTE

deviceId is obtained by deviceManager.getTrustedDeviceListSync. The APIs of the deviceManager module are system interfaces and available only to system applications. For details about how to obtain deviceId, see sync().

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

let kvStore;
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((err) => {
        console.log('removeDeviceData put success');
    }).catch((err) => {
        console.log('put fail ' + JSON.stringify(err));
    });
    const deviceid = 'no_exist_device_id';
    kvStore.removeDeviceData(deviceid).then((err) => {
        console.log('removeDeviceData success');
    }).catch((err) => {
        console.log('removeDeviceData fail ' + JSON.stringify(err));
    });
    kvStore.get(KEY_TEST_STRING_ELEMENT).then((data) => {
        console.log('get success data:' + data);
    }).catch((err) => {
        console.log('RemoveDeviceData get fail ' + JSON.stringify(err));
    });
}catch(e) {
    console.log('RemoveDeviceData e ' + e);
}

sync

sync(deviceIds: string[], mode: SyncMode, delayMs?: number): void

Synchronizes the KV store manually.

NOTE

deviceIds is the networkId in DeviceInfo, which is obtained by deviceManager.getTrustedDeviceListSync. The APIs of the deviceManager module are system interfaces and available only to system applications.

Required permissions: ohos.permission.DISTRIBUTED_DATASYNC

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Example

import deviceManager from '@ohos.distributedHardware.deviceManager';

let devManager;
let kvStore;
const KEY_TEST_SYNC_ELEMENT = 'key_test_sync';
const VALUE_TEST_SYNC_ELEMENT = 'value-string-001';
// create deviceManager
deviceManager.createDeviceManager('bundleName', (err, value) => {
  if (!err) {
    devManager = value;
    let deviceIds = [];
    if (devManager != null) {
      var devices = devManager.getTrustedDeviceListSync();
      for (var i = 0; i < devices.length; i++) {
        deviceIds[i] = devices[i].networkId;
      }
    }
    try {
      kvStore.on('syncComplete', function (data) {
        console.log('Sync dataChange');
      });
      kvStore.put(KEY_TEST_SYNC_ELEMENT + 'testSync101', VALUE_TEST_SYNC_ELEMENT, function (err, data) {
        if (err != undefined) {
          console.log("put err: " + JSON.stringify(err));
          return;
        }
        console.log('Succeeded in putting data');
        const mode = distributedData.SyncMode.PULL_ONLY;
        kvStore.sync(deviceIds, mode, 1000);
      });
    } catch (e) {
      console.log('Sync e' + e);
    }
  }
});

on('dataChange')⁸⁺

on(event: 'dataChange', type: SubscribeType, listener: Callback<ChangeNotification>): void

Subscribes to data changes of the specified type.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Example

let kvStore;
kvStore.on('dataChange', distributedData.SubscribeType.SUBSCRIBE_TYPE_LOCAL, function (data) {
    console.log("dataChange callback call data: " + JSON.stringify(data));
});

on('syncComplete')⁸⁺

on(event: 'syncComplete', syncCallback: Callback<Array<[string, number]>>): void

Subscribes to synchronization complete events.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Example

let kvStore;
const KEY_TEST_FLOAT_ELEMENT = 'key_test_float';
const VALUE_TEST_FLOAT_ELEMENT = 321.12;
try {
    kvStore.on('syncComplete', function (data) {
        console.log('syncComplete ' + data)
    });
    kvStore.put(KEY_TEST_FLOAT_ELEMENT, VALUE_TEST_FLOAT_ELEMENT).then((data) => {
        console.log('syncComplete put success');
    }).catch((error) => {
        console.log('syncComplete put fail ' + error);
    });
}catch(e) {
    console.log('syncComplete put e ' + e);
}

off('dataChange')⁸⁺

off(event:'dataChange', listener?: Callback<ChangeNotification>): void

Unsubscribes from data changes.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Example

let kvStore;
class KvstoreModel {
    call(data) {
        console.log("dataChange: " + data);
    }
    subscribeDataChange() {
        if (kvStore != null) {
            kvStore.on('dataChange', distributedData.SubscribeType.SUBSCRIBE_TYPE_REMOTE, this.call);
        }
    }
    unsubscribeDataChange() {
        if (kvStore != null) {
            kvStore.off('dataChange', this.call);
        }
    }
}

off('syncComplete')⁸⁺

off(event: 'syncComplete', syncCallback?: Callback<Array<[string, number]>>): void

Unsubscribes from synchronization complete events.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Example

let kvStore;
class KvstoreModel {
    call(data) {
        console.log("syncComplete: " + data);
    }
    subscribeSyncComplete() {
        if (kvStore != null) {
            kvStore.on('syncComplete', this.call);
        }
    }
    unsubscribeSyncComplete() {
        if (kvStore != null) {
            kvStore.off('syncComplete', this.call);
        }
    }
}

setSyncParam⁸⁺

setSyncParam(defaultAllowedDelayMs: number, callback: AsyncCallback<void>): void

Sets the default delay allowed for KV store synchronization. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Example

let kvStore;
try {
    const defaultAllowedDelayMs = 500;
    kvStore.setSyncParam(defaultAllowedDelayMs, function (err,data) {
        console.log('SetSyncParam put success');
    });
}catch(e) {
    console.log('testSingleKvStoreSetSyncParam e ' + e);
}

setSyncParam⁸⁺

setSyncParam(defaultAllowedDelayMs: number): Promise<void>

Sets the default delay allowed for KV store synchronization. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Return value

Example

let kvStore;
try {
    const defaultAllowedDelayMs = 500;
    kvStore.setSyncParam(defaultAllowedDelayMs).then((err) => {
        console.log('SetSyncParam put success');
    }).catch((err) => {
        console.log('SetSyncParam put fail ' + JSON.stringify(err));
    });
}catch(e) {
    console.log('SetSyncParam e ' + e);
}

getSecurityLevel⁸⁺

getSecurityLevel(callback: AsyncCallback<SecurityLevel>): void

Obtains the security level of this KV store. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Parameters

Example

let kvStore;
try {
    kvStore.getSecurityLevel(function (err,data) {
        console.log('getSecurityLevel success');
    });
}catch(e) {
    console.log('GetSecurityLevel e ' + e);
}

getSecurityLevel⁸⁺

getSecurityLevel(): Promise<SecurityLevel>

Obtains the security level of this KV store. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.KVStore.Core

Return value

Example

let kvStore;
try {
    kvStore.getSecurityLevel().then((data) => {
        console.log(' getSecurityLevel success');
    }).catch((err) => {
        console.log('getSecurityLevel fail ' + JSON.stringify(err));
    });
}catch(e) {
    console.log('GetSecurityLevel e ' + e);
}

DeviceKVStore⁸⁺

Provides methods to query and synchronize data in a device KV store. This class inherits from KVStore.

Data is distinguished by device in a device KV store. Each device can only write and modify its own data. Data of other devices is read-only and cannot be modified.

For example, a device KV store can be used to implement image sharing between devices. The images of other devices can be viewed, but not be modified or deleted.

Before calling any method in DeviceKVStore, you must use getKVStore to obtain a DeviceKVStore object.

get⁸⁺

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

Obtains a string value that matches the specified device ID and key. This API uses an asynchronous callback to return the result.

NOTE

deviceId is obtained by deviceManager.getTrustedDeviceListSync. The APIs of the deviceManager module are system interfaces and available only to system applications. For details about how to obtain deviceId, see sync().

System capability: SystemCapability.DistributedDataManager.KVStore.DistributedKVStore

Parameters

Example

let kvStore;
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 function (err,data) {
        console.log('put success');
        kvStore.get('localDeviceId', KEY_TEST_STRING_ELEMENT, function (err,data) {
            console.log('get success');
        });
    })
}catch(e) {
    console.log('get e' + e);
}

get⁸⁺

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

Obtains a string value that matches the specified device ID and key. This API uses a promise to return the result.

NOTE

deviceId is obtained by deviceManager.getTrustedDeviceListSync. The APIs of the deviceManager module are system interfaces and available only to system applications. For details about how to obtain deviceId, see sync().

System capability: SystemCapability.DistributedDataManager.KVStore.DistributedKVStore

Parameters

Return value

Example

let kvStore;
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).then(async (data) => {
        console.log(' put success');
        kvStore.get('localDeviceId', KEY_TEST_STRING_ELEMENT).then((data) => {
            console.log('get success');
        }).catch((err) => {
            console.log('get fail ' + JSON.stringify(err));
        });
    }).catch((error) => {
        console.log('put error' + error);
    });
} catch (e) {
    console.log('Get e ' + e);
}

getEntries⁸⁺

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

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

NOTE

deviceId is obtained by deviceManager.getTrustedDeviceListSync. The APIs of the deviceManager module are system interfaces and available only to system applications. For details about how to obtain deviceId, see sync().

System capability: SystemCapability.DistributedDataManager.KVStore.DistributedKVStore

Parameters

Example

let kvStore;
try {
    let entries = [];
    for (var i = 0; i < 10; i++) {
        var key = 'batch_test_string_key';
        var entry = {
            key : key + i,
            value : {
                type : distributedData.ValueType.STRING,
                value : 'batch_test_string_value'
            }
        }
        entries.push(entry);
    }
    console.log('entries: ' + entries);
    kvStore.putBatch(entries, async function (err,data) {
        console.log('putBatch success');
        kvStore.getEntries('localDeviceId', 'batch_test_string_key', function (err,entries) {
            console.log('getEntries success');
            console.log('entries.length: ' + entries.length);
            console.log('entries[0]: ' + JSON.stringify(entries[0]));
        });
    });
}catch(e) {
    console.log('PutBatch e ' + e);
}

getEntries⁸⁺

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

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

NOTE

deviceId is obtained by deviceManager.getTrustedDeviceListSync. The APIs of the deviceManager module are system interfaces and available only to system applications. For details about how to obtain deviceId, see sync().

System capability: SystemCapability.DistributedDataManager.KVStore.DistributedKVStore

Parameters

Return value

Example

let kvStore;
try {
    let entries = [];
    for (var i = 0; i < 10; i++) {
        var key = 'batch_test_string_key';
        var entry = {
            key : key + i,
            value : {
                type : distributedData.ValueType.STRING,
                value : 'batch_test_string_value'
            }
        }
        entries.push(entry);
    }
    console.log('entries: ' + entries);
    kvStore.putBatch(entries).then(async (err) => {
        console.log('putBatch success');
        kvStore.getEntries('localDeviceId', 'batch_test_string_key').then((entries) => {
            console.log('getEntries success');
            console.log('entries.length: ' + entries.length);
            console.log('entries[0]: ' + JSON.stringify(entries[0]));
            console.log('entries[0].value: ' + JSON.stringify(entries[0].value));
            console.log('entries[0].value.value: ' + entries[0].value.value);
        }).catch((err) => {
            console.log('getEntries fail ' + JSON.stringify(err));
        });
    }).catch((err) => {
        console.log('putBatch fail ' + JSON.stringify(err));
    });
}catch(e) {
    console.log('PutBatch e ' + e);
}

getEntries⁸⁺

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.DistributedKVStore

Parameters

Example

let kvStore;
try {
    var arr = new Uint8Array([21,31]);
    let entries = [];
    for (var i = 0; i < 10; i++) {
        var key = 'batch_test_bool_key';
        var entry = {
            key : key + i,
            value : {
                type : distributedData.ValueType.BYTE_ARRAY,
                value : arr
            }
        }
        entries.push(entry);
    }
    console.log('entries: ' + JSON.stringify(entries));
    kvStore.putBatch(entries, async function (err,data) {
        console.log('putBatch success');
        const query = new distributedData.Query();
        query.prefixKey("batch_test");
        query.deviceId('localDeviceId');
        kvStore.getEntries(query, function (err,entries) {
            console.log('getEntries success');
            console.log('entries.length: ' + entries.length);
            console.log('entries[0]: ' + JSON.stringify(entries[0]));
        });
    });
    console.log('GetEntries success');
}catch(e) {
    console.log('GetEntries e ' + e);
}

getEntries⁸⁺

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.DistributedKVStore

Parameters

Return value

Example

let kvStore;
try {
    var arr = new Uint8Array([21,31]);
    let entries = [];
    for (var i = 0; i < 10; i++) {
        var key = 'batch_test_bool_key';
        var entry = {
            key : key + i,
            value : {
                type : distributedData.ValueType.BYTE_ARRAY,
                value : arr
            }
        }
        entries.push(entry);
    }
    console.log('entries: ' + JSON.stringify(entries));
    kvStore.putBatch(entries).then(async (err) => {
        console.log('putBatch success');
        const query = new distributedData.Query();
        query.prefixKey("batch_test");
        kvStore.getEntries(query).then((entries) => {
            console.log('getEntries success');
        }).catch((err) => {
            console.log('getEntries fail ' + JSON.stringify(err));
        });
    }).catch((err) => {
        console.log('GetEntries putBatch fail ' + JSON.stringify(err))
    });
    console.log('GetEntries success');
}catch(e) {
    console.log('GetEntries e ' + e);
}

getEntries⁸⁺

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

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

NOTE

deviceId is obtained by deviceManager.getTrustedDeviceListSync. The APIs of the deviceManager module are system interfaces and available only to system applications. For details about how to obtain deviceId, see sync().

System capability: SystemCapability.DistributedDataManager.KVStore.DistributedKVStore

Parameters

Example

let kvStore;
try {
    var arr = new Uint8Array([21,31]);
    let entries = [];
    for (var i = 0; i < 10; i++) {
        var key = 'batch_test_bool_key';
        var entry = {
            key : key + i,
            value : {
                type : distributedData.ValueType.BYTE_ARRAY,
                value : arr
            }
        }
        entries.push(entry);
    }
    console.log('entries: ' + JSON.stringify(entries));
    kvStore.putBatch(entries, async function (err,data) {
        console.log('putBatch success');
        var query = new distributedData.Query();
        query.deviceId('localDeviceId');
        query.prefixKey("batch_test");
        kvStore.getEntries('localDeviceId', query, function (err,entries) {
            console.log('getEntries success');
            console.log('entries.length: ' + entries.length);
            console.log('entries[0]: ' + JSON.stringify(entries[0]));
        })
    });
    console.log('GetEntries success');
}catch(e) {
    console.log('GetEntries e ' + e);
}

getEntries⁸⁺

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

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

NOTE

deviceId is obtained by deviceManager.getTrustedDeviceListSync. The APIs of the deviceManager module are system interfaces and available only to system applications. For details about how to obtain deviceId, see sync().

System capability: SystemCapability.DistributedDataManager.KVStore.DistributedKVStore

Parameters

Return value

Example

let kvStore;
try {
    var arr = new Uint8Array([21,31]);
    let entries = [];
    for (var i = 0; i < 10; i++) {
        var key = 'batch_test_bool_key';
        var entry = {
            key : key + i,
            value : {
                type : distributedData.ValueType.BYTE_ARRAY,
                value : arr
            }
        }
        entries.push(entry);
    }
    console.log('entries: ' + JSON.stringify(entries));
    kvStore.putBatch(entries).then(async (err) => {
        console.log('putBatch success');
        var query = new distributedData.Query();
        query.deviceId('localDeviceId');
        query.prefixKey("batch_test");
        kvStore.getEntries('localDeviceId', query).then((entries) => {
            console.log('getEntries success');
        }).catch((err) => {
            console.log('getEntries fail ' + JSON.stringify(err));
        });
    }).catch((err) => {
        console.log('putBatch fail ' + JSON.stringify(err));
    });
    console.log('GetEntries success');
}catch(e) {
    console.log('GetEntries e ' + e);
}

getResultSet⁸⁺

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

Obtains a KvStoreResultSet object that matches the specified device ID and key prefix. This API uses an asynchronous callback to return the result.

NOTE

deviceId is obtained by deviceManager.getTrustedDeviceListSync. The APIs of the deviceManager module are system interfaces and available only to system applications. For details about how to obtain deviceId, see sync().

System capability: SystemCapability.DistributedDataManager.KVStore.DistributedKVStore

Parameters

Example

let kvStore;
try {
    let resultSet;
    kvStore.getResultSet('localDeviceId', 'batch_test_string_key', async function (err, result) {
        console.log('getResultSet succeed.');
        resultSet = result;
        kvStore.closeResultSet(resultSet, function (err, data) {
            console.log('closeResultSet success');
        })
    });
}catch(e) {
    console.log('GetResultSet e ' + e);
}

getResultSet⁸⁺

getResultSet(deviceId: string, keyPrefix: string): Promise<KvStoreResultSet>

Obtains a KvStoreResultSet object that matches the specified device ID and key prefix. This API uses a promise to return the result.

NOTE

deviceId is obtained by deviceManager.getTrustedDeviceListSync. The APIs of the deviceManager module are system interfaces and available only to system applications. For details about how to obtain deviceId, see sync().

System capability: SystemCapability.DistributedDataManager.KVStore.DistributedKVStore

Parameters

Return value

Example

let kvStore;
try {
    let resultSet;
    kvStore.getResultSet('localDeviceId', 'batch_test_string_key').then((result) => {
        console.log('getResultSet succeed.');
        resultSet = result;
    }).catch((err) => {
        console.log('getResultSet failed: ' + JSON.stringify(err));
    });
    kvStore.closeResultSet(resultSet).then((err) => {
        console.log('closeResultSet success');
    }).catch((err) => {
        console.log('closeResultSet fail ' + JSON.stringify(err));
    });
}catch(e) {
    console.log('GetResultSet e ' + e);
}

getResultSet⁸⁺

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.DistributedKVStore

Parameters

Example

let kvStore;
try {
    let resultSet;
    let entries = [];
    for (var i = 0; i < 10; i++) {
        var key = 'batch_test_string_key';
        var entry = {
            key : key + i,
            value : {
                type : distributedData.ValueType.STRING,
                value : 'batch_test_string_value'
            }
        }
        entries.push(entry);
    }
    kvStore.putBatch(entries, async function (err, data) {
        console.log('putBatch success');
        const query = new distributedData.Query();
        query.prefixKey("batch_test");
        query.deviceId('localDeviceId');
        kvStore.getResultSet(query, async function (err, result) {
            console.log('getResultSet succeed.');
            resultSet = result;
            kvStore.closeResultSet(resultSet, function (err, data) {
                console.log('closeResultSet success');
            })
        });
    });
} catch(e) {
    console.log('GetResultSet e ' + e);
}

getResultSet⁸⁺

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.DistributedKVStore

Parameters

Return value

Example

let kvStore;
try {
    let resultSet;
    let entries = [];
    for (var i = 0; i < 10; i++) {
        var key = 'batch_test_string_key';
        var entry = {
            key : key + i,
            value : {
                type : distributedData.ValueType.STRING,
                value : 'batch_test_string_value'
            }
        }
        entries.push(entry);
    }
    kvStore.putBatch(entries).then(async (err) => {
        console.log('putBatch success');
    }).catch((err) => {
        console.log('putBatch fail ' + err);
    });
    const query = new distributedData.Query();
    query.deviceId('localDeviceId');
    query.prefixKey("batch_test");
    console.log("GetResultSet " + query.getSqlLike());
    kvStore.getResultSet(query).then((result) => {
        console.log('getResultSet succeed.');
        resultSet = result;
    }).catch((err) => {
        console.log('getResultSet failed: ' + JSON.stringify(err));
    });
    kvStore.closeResultSet(resultSet).then((err) => {
        console.log('closeResultSet success');
    }).catch((err) => {
        console.log('closeResultSet fail ' + JSON.stringify(err));
    });
}catch(e) {
    console.log('GetResultSet e ' + e);
}

getResultSet⁸⁺

getResultSet(deviceId: string, query: Query, callback: AsyncCallback<KvStoreResultSet>): void

Obtains a KvStoreResultSet object that matches the specified device ID and Query object. This API uses an asynchronous callback to return the result.

NOTE

deviceId is obtained by deviceManager.getTrustedDeviceListSync. The APIs of the deviceManager module are system interfaces and available only to system applications. For details about how to obtain deviceId, see sync().