harmony 鸿蒙@ohos.data.distributedData (Distributed Data Management)
@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The APIs provided by this module are no longer maintained since API version 9.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
Name | Type | Mandatory | Description |
---|---|---|---|
config | KVManagerConfig | Yes | Configuration of the KVManager instance, including the bundle name and user information of the caller. |
callback | AsyncCallback<KVManager> | Yes | Callback invoked to return the KVManager instance created. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
config | KVManagerConfig | Yes | Configuration of the KVManager instance, including the bundle name and user information of the caller. |
Return value
Type | Description |
---|---|
Promise<KVManager> | Promise used to return the KVManager instance created. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
userInfo | UserInfo | Yes | User information. |
bundleName | string | Yes | Bundle name of the caller. |
UserInfo
Defines user information.
System capability: SystemCapability.DistributedDataManager.KVStore.Core
Name | Type | Mandatory | Description |
---|---|---|---|
userId | string | No | User ID. The default value is 0. |
userType | UserType | No | User type. The default value is 0. |
UserType
Enumerates the user types.
System capability: SystemCapability.DistributedDataManager.KVStore.Core
Name | Value | Description |
---|---|---|
SAME_USER_ID | 0 | User who logs in to different devices using the same account. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
storeId | string | Yes | Unique identifier of the KV store. The length cannot exceed MAX_STORE_ID_LENGTH. |
options | Options | Yes | Configuration of the KV store. |
callback | AsyncCallback<T> | Yes | Callback invoked to return the KV store instance created. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
storeId | string | Yes | Unique identifier of the KV store. The length cannot exceed MAX_STORE_ID_LENGTH. |
options | Options | Yes | Configuration of the KV store. |
Return value
Type | Description |
---|---|
Promise<T>, <T extends KVStore> | Promise used to return the KV store instance created. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
appId | string | Yes | Bundle name of the app that invokes the KV store. |
storeId | string | Yes | Unique identifier of the KV store to close. The length cannot exceed MAX_STORE_ID_LENGTH. |
kvStore | KVStore | Yes | KV store to close. |
callback | AsyncCallback<void> | Yes | Callback invoked to return the result. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
appId | string | Yes | Bundle name of the app that invokes the KV store. |
storeId | string | Yes | Unique identifier of the KV store to close. The length cannot exceed MAX_STORE_ID_LENGTH. |
kvStore | KVStore | Yes | KV store to close. |
Return value
Type | Description |
---|---|
Promise<void> | Promise that returns no 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
Name | Type | Mandatory | Description |
---|---|---|---|
appId | string | Yes | Bundle name of the app that invokes the KV store. |
storeId | string | Yes | Unique identifier of the KV store to delete. The length cannot exceed MAX_STORE_ID_LENGTH. |
callback | AsyncCallback<void> | Yes | Callback invoked to return the result. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
appId | string | Yes | Bundle name of the app that invokes the KV store. |
storeId | string | Yes | Unique identifier of the KV store to delete. The length cannot exceed MAX_STORE_ID_LENGTH. |
Return value
Type | Description |
---|---|
Promise<void> | Promise that returns no 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
Name | Type | Mandatory | Description |
---|---|---|---|
appId | string | Yes | Bundle name of the app that invokes the KV store. |
callback | AsyncCallback<string[]> | Yes | Callback invoked to return the IDs of all created KV stores. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
appId | string | Yes | Bundle name of the app that invokes the KV store. |
Return value
Type | Description |
---|---|
Promise<string[]> | Promise used to return the IDs of all created KV stores. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
event | string | Yes | Event to subscribe to. The value is distributedDataServiceDie, which indicates a service status change event. |
deathCallback | Callback<void> | Yes | Callback invoked to return a service status change event. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
event | string | Yes | Event to unsubscribe from. The value is distributedDataServiceDie, which indicates a service status change event. |
deathCallback | Callback<void> | No | Callback for the service status change event. If the callback is not specified, all subscriptions to the service status change event are canceled. |
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.
Name | Type | Mandatory | Description |
---|---|---|---|
createIfMissing | boolean | No | Whether to create a KV store if the database file does not exist. The default value is true, which means to create a KV store. System capability: SystemCapability.DistributedDataManager.KVStore.Core |
encrypt | boolean | No | Whether to encrypt the KV store. The default value is false, which means the KV store is not encrypted. System capability: SystemCapability.DistributedDataManager.KVStore.Core |
backup | boolean | No | Whether to back up the KV store. The default value is true, which means to back up the KV store. System capability: SystemCapability.DistributedDataManager.KVStore.Core |
autoSync | boolean | No | Whether to automatically synchronize database files. The default value is false, which means the database files are manually synchronized. System capability: SystemCapability.DistributedDataManager.KVStore.Core Required permissions: ohos.permission.DISTRIBUTED_DATASYNC |
kvStoreType | KVStoreType | No | Type of the KV store to create. The default value is DEVICE_COLLABORATION, which indicates a device KV store. System capability: SystemCapability.DistributedDataManager.KVStore.Core |
securityLevel | SecurityLevel | Yes | Security level (S1 to S4) of the KV store. System capability: SystemCapability.DistributedDataManager.KVStore.Core |
schema8+ | Schema | No | Schema used to define the values stored in the KV store. The default value is undefined, which means no schema is used. System capability: SystemCapability.DistributedDataManager.KVStore.DistributedKVStore |
KVStoreType
Enumerates the KV store types.
Name | Value | Description |
---|---|---|
DEVICE_COLLABORATION | 0 | Device KV store. The device KV store manages data by device, which eliminates conflicts. Data can be queried by device. System capability: SystemCapability.DistributedDataManager.KVStore.DistributedKVStore |
SINGLE_VERSION | 1 | Single KV store. The single KV store does not differentiate data by device. If the same key is modified by different devices, the data will be overwritten. System capability: SystemCapability.DistributedDataManager.KVStore.Core |
MULTI_VERSION | 2 | Multi-version KV store. This type is not supported currently. System capability: SystemCapability.DistributedDataManager.KVStore.DistributedKVStore |
SecurityLevel
Enumerates the KV store security levels.
Name | Value | Description |
---|---|---|
NO_LEVEL | 0 | No security level is set for the KV store (deprecated). System capability: SystemCapability.DistributedDataManager.KVStore.DistributedKVStore |
S0 | 1 | The KV store security level is public (deprecated). System capability: SystemCapability.DistributedDataManager.KVStore.Core |
S1 | 2 | The KV store security level is low. If data leakage occurs, minor impact will be caused. For example, a KV store that contains system data such as wallpapers. System capability: SystemCapability.DistributedDataManager.KVStore.Core |
S2 | 3 | The KV store security level is medium. If data leakage occurs, moderate impact will be caused. For example, a KV store that contains information created by users or call records such as audio or video clips. System capability: SystemCapability.DistributedDataManager.KVStore.Core |
S3 | 5 | The KV store security level is high. If data leakage occurs, major impact will be caused. For example, a KV store that contains information such as user fitness, health, and location data. System capability: SystemCapability.DistributedDataManager.KVStore.Core |
S4 | 6 | The KV store security level is critical. If data leakage occurs, severe impact will be caused. For example, a KV store that contains information such as authentication credentials and financial data. System capability: SystemCapability.DistributedDataManager.KVStore.Core |
Constants
Defines the KV store constants.
System capability: SystemCapability.DistributedDataManager.KVStore.Core
Name | Value | Description |
---|---|---|
MAX_KEY_LENGTH | 1024 | Maximum length of a key in the KV store, in bytes. |
MAX_VALUE_LENGTH | 4194303 | Maximum length of a value in the KV store, in bytes. |
MAX_KEY_LENGTH_DEVICE | 896 | Maximum length of a device key, in bytes. |
MAX_STORE_ID_LENGTH | 128 | Maximum length of a KV store ID, in bytes. |
MAX_QUERY_LENGTH | 512000 | Maximum query length, in bytes. |
MAX_BATCH_SIZE | 128 | Maximum number of batch operations. |
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
Name | Type | Readable | Writable | Description |
---|---|---|---|---|
root8+ | FieldNode | Yes | Yes | JSON root object. |
indexes8+ | Array<string> | Yes | Yes | String array in JSON format. |
mode8+ | number | Yes | Yes | Schema mode. |
skip8+ | number | Yes | Yes | Size of a skip of the schema. |
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
Name | Type | Readable | Writable | Description |
---|---|---|---|---|
nullable8+ | boolean | Yes | Yes | Whether the database field can be null. |
default8+ | string | Yes | Yes | Default value of a FieldNode. |
type8+ | number | Yes | Yes | Value of the data type corresponding to the specified node. |
constructor8+
constructor(name: string)
A constructor used to create a FieldNode instance with a string field.
System capability: SystemCapability.DistributedDataManager.KVStore.DistributedKVStore
Parameters
Name | Type | Mandatory | Description |
---|---|---|---|
name | string | Yes | Value of FieldNode. |
appendChild8+
appendChild(child: FieldNode): boolean
Appends a child node to this FieldNode.
System capability: SystemCapability.DistributedDataManager.KVStore.DistributedKVStore
Parameters
Name | Type | Mandatory | Description |
---|---|---|---|
child | FieldNode | Yes | Child node to append. |
Return value
Type | Description |
---|---|
boolean | Returns true if the operation is successful; returns false otherwise. |
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
Type | Description |
---|---|
number | Total number of rows obtained. |
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
Type | Description |
---|---|
number | Current data read position obtained. |
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
Type | Description |
---|---|
boolean | Returns true if the operation is successful; returns false otherwise. |
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
Type | Description |
---|---|
boolean | Returns true if the operation is successful; returns false otherwise. |
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
Type | Description |
---|---|
boolean | Returns true if the operation is successful; returns false otherwise. |
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
Type | Description |
---|---|
boolean | Returns true if the operation is successful; returns false otherwise. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
offset | number | Yes | Offset to move the data read position. A negative value means to move backward, and a positive value means to move forward. |
Return value
Type | Description |
---|---|
boolean | Returns true if the operation is successful; returns false otherwise. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
position | number | Yes | Absolute position to move to. |
Return value
Type | Description |
---|---|
boolean | Returns true if the operation is successful; returns false otherwise. |
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
Type | Description |
---|---|
boolean | Returns true if the first row is being read; returns false otherwise. |
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
Type | Description |
---|---|
boolean | Returns true if the last row is being read; returns false otherwise. |
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
Type | Description |
---|---|
boolean | Returns true if the data read position is before the first row; returns false otherwise. |
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
Type | Description |
---|---|
boolean | Returns true if the data read position is after the last row; returns false otherwise. |
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
Type | Description |
---|---|
Entry | KV pair obtained. |
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
Type | Description |
---|---|
Query | Query object reset. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
fieId | string | Yes | Field to match. It cannot contain ‘^’. |
value | number|string|boolean | Yes | Value specified. |
Return value
Type | Description |
---|---|
Query | Query object created. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
fieId | string | Yes | Field to match. It cannot contain ‘^’. |
value | number|string|boolean | Yes | Value specified. |
Return value
Type | Description |
---|---|
Query | Query object created. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
fieId | string | Yes | Field to match. It cannot contain ‘^’. |
value | number|string|boolean | Yes | Value specified. |
Return value
Type | Description |
---|---|
Query | Query object created. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
fieId | string | Yes | Field to match. It cannot contain ‘^’. |
value | number|string | Yes | Value specified. |
Return value
Type | Description |
---|---|
Query | Query object created. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
fieId | string | Yes | Field to match. It cannot contain ‘^’. |
value | number|string | Yes | Value specified. |
Return value
Type | Description |
---|---|
Query | Query object created. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
fieId | string | Yes | Field to match. It cannot contain ‘^’. |
value | number|string | Yes | Value specified. |
Return value
Type | Description |
---|---|
Query | Query object created. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
fieId | string | Yes | Field to match. It cannot contain ‘^’. |
Return value
Type | Description |
---|---|
Query | Query object created. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
fieId | string | Yes | Field to match. It cannot contain ‘^’. |
valueList | number[] | Yes | List of numbers. |
Return value
Type | Description |
---|---|
Query | Query object created. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
fieId | string | Yes | Field to match. It cannot contain ‘^’. |
valueList | string[] | Yes | List of strings. |
Return value
Type | Description |
---|---|
Query | Query object created. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
fieId | string | Yes | Field to match. It cannot contain ‘^’. |
valueList | number[] | Yes | List of numbers. |
Return value
Type | Description |
---|---|
Query | Query object created. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
fieId | string | Yes | Field to match. It cannot contain ‘^’. |
valueList | string[] | Yes | List of strings. |
Return value
Type | Description |
---|---|
Query | Query object created. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
fieId | string | Yes | Field to match. It cannot contain ‘^’. |
value | string | Yes | String specified. |
Return value
Type | Description |
---|---|
Query | Query object created. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
fieId | string | Yes | Field to match. It cannot contain ‘^’. |
value | string | Yes | String specified. |
Return value
Type | Description |
---|---|
Query | Query object created. |
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
Type | Description |
---|---|
Query | Query object created. |
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
Type | Description |
---|---|
Query | Query object created. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
fieId | string | Yes | Field to match. It cannot contain ‘^’. |
Return value
Type | Description |
---|---|
Query | Query object created. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
fieId | string | Yes | Field to match. It cannot contain ‘^’. |
Return value
Type | Description |
---|---|
Query | Query object created. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
total | number | Yes | Number of results to query. |
offset | number | Yes | Start position for query. |
Return value
Type | Description |
---|---|
Query | Query object created. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
fieId | string | Yes | Field to match. It cannot contain ‘^’. |
Return value
Type | Description |
---|---|
Query | Query object created. |
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
Type | Description |
---|---|
Query | Query object created. |
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
Type | Description |
---|---|
Query | Query object created. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
prefix | string | Yes | Key prefix. |
Return value
Type | Description |
---|---|
Query | Query object created. |
Example
try {
let query = new distributedData.Query();
query.prefixKey("$.name");
query.prefixKey("0");
console.log("query is " + query.getSqlLike());
query = null;
} catch (e) {
console.log("duplicated calls should be ok :" + e);
}
setSuggestIndex8+
setSuggestIndex(index: string): Query
Creates a Query object with an index preferentially used for query.
System capability: SystemCapability.DistributedDataManager.KVStore.Core
Parameters
Name | Type | Mandatory | Description |
---|---|---|---|
index | string | Yes | Index preferentially used for query. |
Return value
Type | Description |
---|---|
Query | Query object created. |
Example
try {
let query = new distributedData.Query();
query.setSuggestIndex("$.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
Name | Type | Mandatory | Description |
---|---|---|---|
deviceId | string | Yes | Device ID. |
Return value
Type | Description |
---|---|
Query | Query object created. |
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
Type | Description |
---|---|
string | Returns the query statement obtained. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
key | string | Yes | Key of the KV pair to add. It cannot be empty, and the length cannot exceed MAX_KEY_LENGTH. |
value | Uint8Array |string |number |boolean | Yes | Value of the KV pair to add. The value type can be Uint8Array, number, string, or boolean. A value of the Uint8Array or string type cannot exceed MAX_VALUE_LENGTH. |
callback | AsyncCallback<void> | Yes | Callback invoked to return the result. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
key | string | Yes | Key of the KV pair to add. It cannot be empty, and the length cannot exceed MAX_KEY_LENGTH. |
value | Uint8Array |string |number |boolean | Yes | Value of the KV pair to add. The value type can be Uint8Array, number, string, or boolean. A value of the Uint8Array or string type cannot exceed MAX_VALUE_LENGTH. |
Return value
Type | Description |
---|---|
Promise<void> | Promise that returns no 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
Name | Type | Mandatory | Description |
---|---|---|---|
key | string | Yes | Key of the KV pair to delete. It cannot be empty, and the length cannot exceed MAX_KEY_LENGTH. |
callback | AsyncCallback<void> | Yes | Callback invoked to return the result. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
key | string | Yes | Key of the KV pair to delete. It cannot be empty, and the length cannot exceed MAX_KEY_LENGTH. |
Return value
Type | Description |
---|---|
Promise<void> | Promise that returns no 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
Name | Type | Mandatory | Description |
---|---|---|---|
event | string | Yes | Event to subscribe to. The value is dataChange, which indicates a data change event. |
type | SubscribeType | Yes | Type of data change. |
listener | Callback<ChangeNotification> | Yes | Callback invoked to return a data change event. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
event | string | Yes | Event to subscribe to. The value is syncComplete, which indicates a synchronization complete event. |
syncCallback | Callback<Array<[string, number]>> | Yes | Callback invoked to return a synchronization complete event. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
event | string | Yes | Event to unsubscribe from. The value is dataChange, which indicates a data change event. |
listener | Callback<ChangeNotification> | No | Callback for the data change event. If the callback is not specified, all subscriptions to the data change event are canceled. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
event | string | Yes | Event to unsubscribe from. The value is syncComplete, which indicates a synchronization complete event. |
syncCallback | Callback<Array<[string, number]>> | No | Callback for the synchronization complete event. If the callback is not specified, all subscriptions to the synchronization complete event are canceled. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
entries | Entry[] | Yes | KV pairs to insert in batches. |
callback | AsyncCallback<void> | Yes | Callback invoked to return the result. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
entries | Entry[] | Yes | KV pairs to insert in batches. |
Return value
Type | Description |
---|---|
Promise<void> | Promise that returns no 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
Name | Type | Mandatory | Description |
---|---|---|---|
keys | string[] | Yes | KV pairs to delete in batches. |
callback | AsyncCallback<void> | Yes | Callback invoked to return the result. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
keys | string[] | Yes | KV pairs to delete in batches. |
Return value
Type | Description |
---|---|
Promise<void> | Promise that returns no 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
Name | Type | Mandatory | Description |
---|---|---|---|
callback | AsyncCallback<void> | Yes | Callback invoked to return the result. |
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
Type | Description |
---|---|
Promise<void> | Promise that returns no 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
Name | Type | Mandatory | Description |
---|---|---|---|
callback | AsyncCallback<void> | Yes | Callback invoked to return the result. |
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
Type | Description |
---|---|
Promise<void> | Promise that returns no 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
Name | Type | Mandatory | Description |
---|---|---|---|
callback | AsyncCallback<void> | Yes | Callback invoked to return the result. |
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
Type | Description |
---|---|
Promise<void> | Promise that returns no 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
Name | Type | Mandatory | Description |
---|---|---|---|
enabled | boolean | Yes | Whether to enable data synchronization. The value true means to enable data synchronization, and false means the opposite. |
callback | AsyncCallback<void> | Yes | Callback invoked to return the result. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
enabled | boolean | Yes | Whether to enable data synchronization. The value true means to enable data synchronization, and false means the opposite. |
Return value
Type | Description |
---|---|
Promise<void> | Promise that returns no 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
Name | Type | Mandatory | Description |
---|---|---|---|
localLabels | string[] | Yes | Synchronization labels set for the local device. |
remoteSupportLabels | string[] | Yes | Synchronization labels set for remote devices. |
callback | AsyncCallback<void> | Yes | Callback invoked to return the result. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
localLabels | string[] | Yes | Synchronization labels set for the local device. |
remoteSupportLabels | string[] | Yes | Synchronization labels set for remote devices. |
Return value
Type | Description |
---|---|
Promise<void> | Promise that returns no 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
Name | Value | Description |
---|---|---|
SUBSCRIBE_TYPE_LOCAL | 0 | Local data changes. |
SUBSCRIBE_TYPE_REMOTE | 1 | Remote data changes. |
SUBSCRIBE_TYPE_ALL | 2 | Local and remote data changes. |
ChangeNotification
Defines the content of data change notifications, including inserted data, updated data, deleted data, and device ID.
System capability: SystemCapability.DistributedDataManager.KVStore.Core
Name | Type | Mandatory | Description |
---|---|---|---|
insertEntries | Entry[] | Yes | Data inserted. |
updateEntries | Entry[] | Yes | Data updated. |
deleteEntries | Entry[] | Yes | Data deleted. |
deviceId | string | Yes | UUID of the device. |
Entry
Defines the KV pairs stored in the KV store.
System capability: SystemCapability.DistributedDataManager.KVStore.Core
Name | Type | Mandatory | Description |
---|---|---|---|
key | string | Yes | Key of the KV pair stored in the KV store. |
value | Value | Yes | Value of the KV pair stored in the KV store. |
Value
Defines the value object in a KV store.
System capability: SystemCapability.DistributedDataManager.KVStore.Core
Name | Type | Mandatory | Description |
---|---|---|---|
type | ValueType | Yes | Type of the value. |
value | Uint8Array |string |number |boolean | Yes | Value of the KV pair stored in the KV store. |
ValueType
Enumerates the data types.
System capability: SystemCapability.DistributedDataManager.KVStore.Core
Name | Value | Description |
---|---|---|
STRING | 0 | String. |
INTEGER | 1 | Integer. |
FLOAT | 2 | Float (single-precision floating point). |
BYTE_ARRAY | 3 | Byte array. |
BOOLEAN | 4 | Boolean. |
DOUBLE | 5 | Double (double-precision floating point). |
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
Name | Type | Mandatory | Description |
---|---|---|---|
key | string | Yes | Key of the value to obtain. It cannot be empty, and the length cannot exceed MAX_KEY_LENGTH. |
callback | AsyncCallback<Uint8Array |string |boolean |number> | Yes | Callback invoked to return the value obtained. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
key | string | Yes | Key of the value to obtain. It cannot be empty, and the length cannot exceed MAX_KEY_LENGTH. |
Return value
Type | Description |
---|---|
Promise<Uint8Array |string |boolean |number> | Promise used to return the value obtained. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
keyPrefix | string | Yes | Key prefix to match. |
callback | AsyncCallback<Entry[]> | Yes | Callback invoked to return the KV pairs that match the specified prefix. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
keyPrefix | string | Yes | Key prefix to match. |
Return value
Type | Description |
---|---|
Promise<Entry[]> | Promise used to return the KV pairs that match the specified prefix. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
query | Query | Yes | Key prefix to match. |
callback | AsyncCallback<Entry[]> | Yes | Callback invoked to return the KV pairs that match the specified Query object. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
query | Query | Yes | Query object to match. |
Return value
Type | Description |
---|---|
Promise<Entry[]> | Promise used to return the KV pairs that match the specified Query object. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
keyPrefix | string | Yes | Key prefix to match. |
callback | AsyncCallback<KvStoreResultSet> | Yes | Callback invoked to return the result set with the specified prefix. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
keyPrefix | string | Yes | Key prefix to match. |
Return value
Type | Description |
---|---|
Promise<KvStoreResultSet> | Promise used to return the result set with the specified prefix. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
query | Query | Yes | Query object to match. |
callback | AsyncCallback<KvStoreResultSet> | Yes | Callback invoked to return the KvStoreResultSet object obtained. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
query | Query | Yes | Query object to match. |
Return value
Type | Description |
---|---|
Promise<KvStoreResultSet> | Promise used to return the KvStoreResultSet object obtained. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
resultSet | KvStoreResultSet | Yes | KvStoreResultSet object to close. |
callback | AsyncCallback<void> | Yes | Callback invoked to return the result. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
resultSet | KvStoreResultSet | Yes | KvStoreResultSet object to close. |
Return value
Type | Description |
---|---|
Promise<void> | Promise that returns no 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
Name | Type | Mandatory | Description |
---|---|---|---|
query | Query | Yes | Query object to match. |
callback | AsyncCallback<number> | Yes | Callback invoked to return the number of results that match the specified Query object. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
query | Query | Yes | Query object to match. |
Return value
Type | Description |
---|---|
Promise<number> | Promise used to return the number of results obtained. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
deviceId | string | Yes | ID of the target device. |
callback | AsyncCallback<void> | Yes | Callback invoked to return the result. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
deviceId | string | Yes | ID of the target device. |
Return value
Type | Description |
---|---|
Promise<void> | Promise that returns no 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
Name | Type | Mandatory | Description |
---|---|---|---|
deviceIds | string[] | Yes | List of networkIds of the devices in the same networking environment to be synchronized. |
mode | SyncMode | Yes | Synchronization mode. |
delayMs | number | No | Delay time allowed, in milliseconds. The default value is 0. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
event | string | Yes | Event to subscribe to. The value is dataChange, which indicates a data change event. |
type | SubscribeType | Yes | Type of data change. |
listener | Callback<ChangeNotification> | Yes | Callback invoked to return a data change event. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
event | string | Yes | Event to subscribe to. The value is syncComplete, which indicates a synchronization complete event. |
syncCallback | Callback<Array<[string, number]>> | Yes | Callback invoked to return a synchronization complete event. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
event | string | Yes | Event to unsubscribe from. The value is dataChange, which indicates a data change event. |
listener | Callback<ChangeNotification> | No | Callback for the data change event. If the callback is not specified, all subscriptions to the data change event are canceled. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
event | string | Yes | Event to unsubscribe from. The value is syncComplete, which indicates a synchronization complete event. |
syncCallback | Callback<Array<[string, number]>> | No | Callback for the synchronization complete event. If the callback is not specified, all subscriptions to the synchronization complete event are canceled. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
defaultAllowedDelayMs | number | Yes | Default delay allowed for database synchronization, in ms. |
callback | AsyncCallback<void> | Yes | Callback invoked to return the result. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
defaultAllowedDelayMs | number | Yes | Default delay allowed for database synchronization, in ms. |
Return value
Type | Description |
---|---|
Promise<void> | Promise that returns no 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
Name | Type | Mandatory | Description |
---|---|---|---|
callback | AsyncCallback<SecurityLevel> | Yes | Callback invoked to return the security level of the KV store. |
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
Type | Description |
---|---|
Promise<SecurityLevel> | Promise used to return the security level of the KV store. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
deviceId | string | Yes | ID of the target device. |
key | string | Yes | Key to match. |
callback | AsyncCallback<boolean|string|number|Uint8Array> | Yes | Callback invoked to return the value obtained. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
deviceId | string | Yes | ID of the target device. |
key | string | Yes | Key to match. |
Return value
Type | Description |
---|---|
Promise<boolean|string|number|Uint8Array> | Promise used to return the string value that matches the given condition. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
deviceId | string | Yes | ID of the target device. |
keyPrefix | string | Yes | Key prefix to match. |
callback | AsyncCallback<Entry[]> | Yes | Callback invoked to return the KV pairs obtained. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
deviceId | string | Yes | ID of the target device. |
keyPrefix | string | Yes | Key prefix to match. |
Return value
Type | Description |
---|---|
Promise<Entry[]> | Promise used to return all the KV pairs that match the given condition. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
query | Query | Yes | Query object to match. |
callback | AsyncCallback<Entry[]> | Yes | Callback invoked to return the KV pairs obtained. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
query | Query | Yes | Query object to match. |
Return value
Type | Description |
---|---|
Promise<Entry[]> | Promise used to return the KV pairs that match the specified Query object. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
deviceId | string | Yes | ID of the target device. |
query | Query | Yes | Query object to match. |
callback | AsyncCallback<Entry[]> | Yes | Callback invoked to return the KV pairs that match the specified device ID and Query object. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
deviceId | string | Yes | ID of the target device. |
query | Query | Yes | Query object to match. |
Return value
Type | Description |
---|---|
Promise<Entry[]> | Promise used to return the KV pairs that match the specified device ID and Query object. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
deviceId | string | Yes | ID of the target device. |
keyPrefix | string | Yes | Key prefix to match. |
callback | AsyncCallback<KvStoreResultSet> | Yes | Callback invoked to return the KvStoreResultSet object that matches the specified device ID and key prefix. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
deviceId | string | Yes | ID of the target device. |
keyPrefix | string | Yes | Key prefix to match. |
Return value
Type | Description |
---|---|
Promise<KvStoreResultSet> | Promise used to return the KvStoreResultSet object that matches the specified device ID and key prefix. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
query | Query | Yes | Query object to match. |
callback | AsyncCallback<KvStoreResultSet> | Yes | Callback invoked to return the KvStoreResultSet object obtained. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
query | Query | Yes | Query object to match. |
Return value
Type | Description |
---|---|
Promise<KvStoreResultSet> | Promise used to return the KvStoreResultSet object that matches the specified Query object. |
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().
System capability: SystemCapability.DistributedDataManager.KVStore.DistributedKVStore
Parameters
Name | Type | Mandatory | Description |
---|---|---|---|
deviceId | string | Yes | ID of the target device. |
query | Query | Yes | Query object to match. |
callback | AsyncCallback<KvStoreResultSet> | Yes | Callback invoked to return the KvStoreResultSet object that matches the specified device ID and Query object. |
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('localDeviceId', 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(deviceId: string, query: Query): Promise<KvStoreResultSet>
Obtains a KvStoreResultSet object that matches 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
Name | Type | Mandatory | Description |
---|---|---|---|
deviceId | string | Yes | ID of the target device. |
query | Query | Yes | Query object to match. |
Return value
Type | Description |
---|---|
Promise<KvStoreResultSet> | Promise used to return the KvStoreResultSet object that matches the specified device ID and Query object. |
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('GetResultSet putBatch success');
}).catch((err) => {
console.log('PutBatch putBatch fail ' + JSON.stringify(err));
});
const query = new distributedData.Query();
query.prefixKey("batch_test");
kvStore.getResultSet('localDeviceId', query).then((result) => {
console.log('GetResultSet getResultSet succeed.');
resultSet = result;
}).catch((err) => {
console.log('GetResultSet getResultSet failed: ' + JSON.stringify(err));
});
query.deviceId('localDeviceId');
console.log("GetResultSet " + query.getSqlLike());
kvStore.closeResultSet(resultSet).then((err) => {
console.log('GetResultSet closeResultSet success');
}).catch((err) => {
console.log('GetResultSet closeResultSet fail ' + JSON.stringify(err));
});
}catch(e) {
console.log('GetResultSet e ' + e);
}
closeResultSet8+
closeResultSet(resultSet: KvStoreResultSet, callback: AsyncCallback<void>): void
Closes the KvStoreResultSet object obtained by DeviceKVStore.getResultSet. This API uses an asynchronous callback to return the result.
System capability: SystemCapability.DistributedDataManager.KVStore.DistributedKVStore
Parameters
Name | Type | Mandatory | Description |
---|---|---|---|
resultSet | KvStoreResultSet | Yes | KvStoreResultSet object to close. |
callback | AsyncCallback<void> | Yes | Callback invoked to return the result. |
Example
let kvStore;
try {
console.log('CloseResultSet success');
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 DeviceKVStore.getResultSet. This API uses a promise to return the result.
System capability: SystemCapability.DistributedDataManager.KVStore.DistributedKVStore
Parameters
Name | Type | Mandatory | Description |
---|---|---|---|
resultSet | KvStoreResultSet | Yes | KvStoreResultSet object to close. |
Return value
Type | Description |
---|---|
Promise<void> | Promise that returns no value. |
Example
let kvStore;
try {
console.log('CloseResultSet success');
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.DistributedKVStore
Parameters
Name | Type | Mandatory | Description |
---|---|---|---|
query | Query | Yes | Query object to match. |
callback | AsyncCallback<number> | Yes | Callback invoked to return the number of results obtained. |
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");
query.deviceId('localDeviceId');
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.DistributedKVStore
Parameters
Name | Type | Mandatory | Description |
---|---|---|---|
query | Query | Yes | Query object to match. |
Return value
Type | Description |
---|---|
Promise<number> | Promise used to return the number of results obtained. |
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");
query.deviceId('localDeviceId');
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);
}
getResultSize8+
getResultSize(deviceId: string, query: Query, callback: AsyncCallback<number>): void;
Obtains the number of results 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().
System capability: SystemCapability.DistributedDataManager.KVStore.DistributedKVStore
Parameters
Name | Type | Mandatory | Description |
---|---|---|---|
deviceId | string | Yes | ID of the target device. |
query | Query | Yes | Query object to match. |
callback | AsyncCallback<number> | Yes | Callback invoked to return the number of results obtained. |
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('localDeviceId', query, async function (err, resultSize) {
console.log('getResultSet succeed.');
});
});
} catch(e) {
console.log('GetResultSize e ' + e);
}
getResultSize8+
getResultSize(deviceId: string, query: Query): Promise<number>
Obtains the number of results that matches 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
Name | Type | Mandatory | Description |
---|---|---|---|
deviceId | string | Yes | ID of the target device. |
query | Query | Yes | Query object to match. |
Return value
Type | Description |
---|---|
Promise<number> | Promise used to return the number of results obtained. |
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));
});
var query = new distributedData.Query();
query.prefixKey("batch_test");
kvStore.getResultSize('localDeviceId', 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 the specified device from this KV store. 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
Name | Type | Mandatory | Description |
---|---|---|---|
deviceId | string | Yes | ID of the target device. |
callback | AsyncCallback<void> | Yes | Callback invoked to return the result. |
Example
let kvStore;
const KEY_TEST_STRING_ELEMENT = 'key_test_string';
const VALUE_TEST_STRING_ELEMENT = 'value-string-001';
try {
kvStore.put(KEY_TEST_STRING_ELEMENT, VALUE_TEST_STRING_ELEMENT, async function (err,data) {
console.log('RemoveDeviceData 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('localDeviceId', 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 the specified device from this KV store. 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
Name | Type | Mandatory | Description |
---|---|---|---|
deviceId | string | Yes | ID of the target device. |
Return value
Type | Description |
---|---|
Promise<void> | Promise that returns no value. |
Example
let kvStore;
const KEY_TEST_STRING_ELEMENT = 'key_test_string';
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('RemoveDeviceData 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('localDeviceId', KEY_TEST_STRING_ELEMENT).then((data) => {
console.log('RemoveDeviceData get success data:' + data);
}).catch((err) => {
console.log('RemoveDeviceData get fail ' + JSON.stringify(err));
});
}catch(e) {
console.log('RemoveDeviceData e ' + e);
}
sync8+
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
Name | Type | Mandatory | Description |
---|---|---|---|
deviceIds | string[] | Yes | networkIds of the devices to be synchronized. |
mode | SyncMode | Yes | Synchronization mode. |
delayMs | number | No | Allowed synchronization delay time, in ms. The default value is 0. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
event | string | Yes | Event to subscribe to. The value is dataChange, which indicates a data change event. |
type | SubscribeType | Yes | Type of data change. |
listener | Callback<ChangeNotification> | Yes | Callback invoked to return a data change event. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
event | string | Yes | Event to subscribe to. The value is syncComplete, which indicates a synchronization complete event. |
syncCallback | Callback<Array<[string, number]>> | Yes | Callback invoked to return a synchronization complete event. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
event | string | Yes | Event to unsubscribe from. The value is dataChange, which indicates a data change event. |
listener | Callback<ChangeNotification> | No | Callback for the data change event. If the callback is not specified, all subscriptions to the data change event are canceled. |
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
Name | Type | Mandatory | Description |
---|---|---|---|
event | string | Yes | Event to unsubscribe from. The value is syncComplete, which indicates a synchronization complete event. |
syncCallback | Callback<Array<[string, number]>> | No | Callback for the synchronization complete event. If the callback is not specified, all subscriptions to the synchronization complete event are canceled. |
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);
}
}
}
SyncMode
Enumerates the synchronization modes.
System capability: SystemCapability.DistributedDataManager.KVStore.Core
Name | Value | Description |
---|---|---|
PULL_ONLY | 0 | Pull data from the peer end to the local end only. |
PUSH_ONLY | 1 | Push data from the local end to the peer end only. |
PUSH_PULL | 2 | Push data from the local end to the peer end and then pull data from the peer end to the local end. |
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