harmony 鸿蒙@ohos.data.rdb (RDB)

2022-08-09
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@ohos.data.rdb (RDB)

The relational database (RDB) manages data based on relational models. With the underlying SQLite database, the RDB provides a complete mechanism for managing local databases. To satisfy different needs in complicated scenarios, the RDB offers a series of methods for performing operations such as adding, deleting, modifying, and querying data, and supports direct execution of SQL statements. The worker threads are not supported.

This module provides the following RDB-related functions:

RdbPredicates: provides predicates indicating the nature, feature, or relationship of a data entity in an RDB store. It is used to define the operation conditions for an RDB store.
RdbStore: provides APIs for managing an RDB store.

NOTE

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

The APIs of this module are no longer maintained since API version 9. You are advised to use @ohos.data.relationalStore.

Modules to Import

import data_rdb from '@ohos.data.rdb';

data_rdb.getRdbStore

getRdbStore(context: Context, config: StoreConfig, version: number, callback: AsyncCallback<RdbStore>): void

Obtains an RDB store. This API uses an asynchronous callback to return the result. You can set parameters for the RDB store based on service requirements and call APIs to perform data operations.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
context	Context	Yes	Application context. For details about the application context of the FA model, see Context. For details about the application context of the stage model, see Context.
config	StoreConfig	Yes	Configuration of the RDB store.
version	number	Yes	RDB store version. Currently, automatic RDB upgrades and downgrades performed based on version is not supported.
callback	AsyncCallback<RdbStore>	Yes	Callback invoked to return the RDB store obtained.

Example

FA model:

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

data_rdb.getRdbStore(this.context, "RdbTest.db", 1, (err, rdbStore) => {
  if (err) {
    console.info("Failed to get RdbStore, err: " + err)
    return
  }
  console.log("Got RdbStore successfully.")
})

Stage model:

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

class EntryAbility extends UIAbility {
  onWindowStageCreate(windowStage: window.WindowStage){
    data_rdb.getRdbStore(this.context, "RdbTest.db", 1, (err: BusinessError, rdbStore: data_rdb.RdbStore) => {
      if (err) {
        console.info("Failed to get RdbStore, err: " + err)
        return
      }
      console.log("Got RdbStore successfully.")
    })
  }
}

data_rdb.getRdbStore

getRdbStore(context: Context, config: StoreConfig, version: number): Promise<RdbStore>

Obtains an RDB store. This API uses a promise to return the result. You can set parameters for the RDB store based on service requirements and call APIs to perform data operations.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
context	Context	Yes	Application context. For details about the application context of the FA model, see Context. For details about the application context of the stage model, see Context.
config	StoreConfig	Yes	Configuration of the RDB store.
version	number	Yes	RDB store version. Currently, automatic RDB upgrades and downgrades performed based on version is not supported.

Return value

Type	Description
Promise<RdbStore>	Promise used to return the RDB store obtained.

Example

FA model:

import featureAbility from '@ohos.ability.featureAbility';

let promise = data_rdb.getRdbStore(this.context, "RdbTest.db", 1);
promise.then(async (rdbStore) => {
  console.log("Got RdbStore successfully.")
}).catch((err: BusinessError) => {
  console.log("Failed to get RdbStore, err: " + err)
})

Stage model:

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

class EntryAbility extends UIAbility {
  onWindowStageCreate(windowStage: window.WindowStage){
    context = this.context
  }
}

// Call getRdbStore.
let promise = data_rdb.getRdbStore(this.context, "RdbTest.db", 1);
promise.then(async (rdbStore: data_rdb.RdbStore) => {
  console.log("Got RdbStore successfully.")
}).catch((err: BusinessError) => {
  console.log("Failed to get RdbStore, err: " + err)
})

data_rdb.deleteRdbStore

deleteRdbStore(context: Context, name: string, callback: AsyncCallback<void>): void

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

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
context	Context	Yes	Application context. For details about the application context of the FA model, see Context. For details about the application context of the stage model, see Context.
name	string	Yes	Name of the RDB store to delete.
callback	AsyncCallback<void>	Yes	Callback invoked to return the result.

Example

FA model:

import featureAbility from '@ohos.ability.featureAbility';

data_rdb.deleteRdbStore(this.context, "RdbTest.db", (err) => {
  if (err) {
    console.info("Failed to delete RdbStore, err: " + err)
    return
  }
  console.log("Deleted RdbStore successfully.")
})

Stage model:

import UIAbility from '@ohos.app.ability.UIAbility';
import window from '@ohos.window';

class EntryAbility extends UIAbility {
  onWindowStageCreate(windowStage: window.WindowStage){
    context = this.context
  }
}

// Call deleteRdbStore.
data_rdb.deleteRdbStore(this.context, "RdbTest.db", (err) => {
  if (err) {
    console.info("Failed to delete RdbStore, err: " + err)
    return
  }
  console.log("Deleted RdbStore successfully.")
})

data_rdb.deleteRdbStore

deleteRdbStore(context: Context, name: string): Promise<void>

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

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
context	Context	Yes	Application context. For details about the application context of the FA model, see Context. For details about the application context of the stage model, see Context.
name	string	Yes	Name of the RDB store to delete.

Return value

Type	Description
Promise<void>	Promise that returns no value.

Example

FA model:

import featureAbility from '@ohos.ability.featureAbility';

let promise = data_rdb.deleteRdbStore(this.context, "RdbTest.db")
promise.then(() => {
  console.log("Deleted RdbStore successfully.")
}).catch((err: BusinessError) => {
  console.info("Failed to delete RdbStore, err: " + err)
})

Stage model:

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

class EntryAbility extends UIAbility {
  onWindowStageCreate(windowStage: window.WindowStage){
    context = this.context
  }
}

// Call deleteRdbStore.
let promise = data_rdb.deleteRdbStore(this.context, "RdbTest.db")
promise.then(()=>{
  console.log("Deleted RdbStore successfully.")
}).catch((err: BusinessError) => {
  console.info("Failed to delete RdbStore, err: " + err)
})

ValueType

Defines the data types allowed.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Type	Description
number	Number.
string	String.
boolean	Boolean.

ValuesBucket

Defines the types of the key and value in a KV pair.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Key Type	Value Type
string	ValueType\| Uint8Array \| null

SyncMode⁸⁺

Defines the database synchronization mode.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Name	Value	Description
SYNC_MODE_PUSH	0	Data is pushed from a local device to a remote device.
SYNC_MODE_PULL	1	Data is pulled from a remote device to a local device.

SubscribeType⁸⁺

Defines the subscription type.

Required permissions: ohos.permission.DISTRIBUTED_DATASYNC

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Name	Value	Description
SUBSCRIBE_TYPE_REMOTE	0	Subscribe to remote data changes.

StoreConfig

Defines the RDB store configuration.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Name	Type	Mandatory	Description
name	string	Yes	Database file name.

RdbPredicates

Defines predicates for an RDB store. This class determines whether the conditional expression for the RDB store is true or false.

constructor

constructor(name: string)

A constructor used to create an RdbPredicates object.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
name	string	Yes	Database table name.

Example

let predicates = new data_rdb.RdbPredicates("EMPLOYEE")

inDevices⁸⁺

inDevices(devices: Array<string>): RdbPredicates

Sets an RdbPredicates to specify the remote devices to connect on the network during distributed database synchronization.

NOTE

The value of devices is obtained by deviceManager.getTrustedDeviceListSync. The APIs of the deviceManager module are system interfaces and available only to system applications.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
devices	Array<string>	Yes	IDs of the remote devices in the same network.

Return value

Type	Description
RdbPredicates	RdbPredicates object created.

Example

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

let dmInstance: deviceManager.DeviceManager;
let deviceIds: Array<string> = [];
let devices: Array<string> = [];

deviceManager.createDeviceManager("com.example.appdatamgrverify", (err: BusinessError, manager: void) => {
  if (err) {
    console.log("create device manager failed, err=" + err);
    return;
  }
  dmInstance = manager;
  devices = dmInstance.getTrustedDeviceListSync();
  for (let i = 0; i < devices.length; i++) {
    deviceIds[i] = devices[i].deviceId;
  }
})

let predicates = new data_rdb.RdbPredicates("EMPLOYEE");
predicates.inDevices(deviceIds);
                                  
let predicates = new data_rdb.RdbPredicates("EMPLOYEE");
predicates.inDevices(deviceIds);

inAllDevices⁸⁺

inAllDevices(): RdbPredicates

Sets an RdbPredicates to specify all remote devices on the network to connect during distributed database synchronization.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Return value

Type	Description
RdbPredicates	RdbPredicates object created.

Example

let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.inAllDevices()

equalTo

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

Sets an RdbPredicates to match the field with data type ValueType and value equal to the specified value.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
field	string	Yes	Column name in the database table.
value	ValueType	Yes	Value to match the RdbPredicates.

Return value

Type	Description
RdbPredicates	RdbPredicates object created.

Example

let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.equalTo("NAME", "lisi")

notEqualTo

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

Sets an RdbPredicates to match the field with data type ValueType and value not equal to the specified value.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
field	string	Yes	Column name in the database table.
value	ValueType	Yes	Value to match the RdbPredicates.

Return value

Type	Description
RdbPredicates	RdbPredicates object created.

Example

let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.notEqualTo("NAME", "lisi")

beginWrap

beginWrap(): RdbPredicates

Adds a left parenthesis to the RdbPredicates.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Return value

Type	Description
RdbPredicates	RdbPredicates with a left parenthesis.

Example

let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.equalTo("NAME", "lisi")
    .beginWrap()
    .equalTo("AGE", 18)
    .or()
    .equalTo("SALARY", 200.5)
    .endWrap()

endWrap

endWrap(): RdbPredicates

Adds a right parenthesis to the RdbPredicates.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Return value

Type	Description
RdbPredicates	RdbPredicates with a right parenthesis.

Example

let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.equalTo("NAME", "lisi")
    .beginWrap()
    .equalTo("AGE", 18)
    .or()
    .equalTo("SALARY", 200.5)
    .endWrap()

or

or(): RdbPredicates

Adds the OR condition to the RdbPredicates.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Return value

Type	Description
RdbPredicates	RdbPredicates with the OR condition.

Example

let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.equalTo("NAME", "Lisa")
    .or()
    .equalTo("NAME", "Rose")

and

and(): RdbPredicates

Adds the AND condition to the RdbPredicates.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Return value

Type	Description
RdbPredicates	RdbPredicates with the AND condition.

Example

let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.equalTo("NAME", "Lisa")
    .and()
    .equalTo("SALARY", 200.5)

contains

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

Sets an RdbPredicates to match a string containing the specified value.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
field	string	Yes	Column name in the database table.
value	string	Yes	Value to match the RdbPredicates.

Return value

Type	Description
RdbPredicates	RdbPredicates object created.

Example

let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.contains("NAME", "os")

beginsWith

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

Sets an RdbPredicates to match a string that starts with the specified value.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
field	string	Yes	Column name in the database table.
value	string	Yes	Value to match the RdbPredicates.

Return value

Type	Description
RdbPredicates	RdbPredicates object created.

Example

let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.beginsWith("NAME", "os")

endsWith

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

Sets an RdbPredicates to match a string that ends with the specified value.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
field	string	Yes	Column name in the database table.
value	string	Yes	Value to match the RdbPredicates.

Return value

Type	Description
RdbPredicates	RdbPredicates object created.

Example

let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.endsWith("NAME", "se")

isNull

isNull(field: string): RdbPredicates

Sets an RdbPredicates to match the field whose value is null.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
field	string	Yes	Column name in the database table.

Return value

Type	Description
RdbPredicates	RdbPredicates object created.

Example

let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.isNull("NAME")

isNotNull

isNotNull(field: string): RdbPredicates

Sets an RdbPredicates to match the field whose value is not null.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
field	string	Yes	Column name in the database table.

Return value

Type	Description
RdbPredicates	RdbPredicates object created.

Example

let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.isNotNull("NAME")

like

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

Sets an RdbPredicates to match a string that is similar to the specified value.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
field	string	Yes	Column name in the database table.
value	string	Yes	Value to match the RdbPredicates.

Return value

Type	Description
RdbPredicates	RdbPredicates object created.

Example

let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.like("NAME", "%os%")

glob

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

Sets an RdbPredicates to match the specified string.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
field	string	Yes	Column name in the database table.
value	string	Yes	Value to match the RdbPredicates. Wildcards are supported. * indicates zero, one, or multiple digits or characters. ? indicates a single digit or character.

Return value

Type	Description
RdbPredicates	RdbPredicates object created.

Example

let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.glob("NAME", "?h*g")

between

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

Sets an RdbPredicates to match the field with data type ValueType and value within the specified range.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
field	string	Yes	Column name in the database table.
low	ValueType	Yes	Minimum value to match the RdbPredicates.
high	ValueType	Yes	Maximum value to match the RdbPredicates.

Return value

Type	Description
RdbPredicates	RdbPredicates object created.

Example

let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.between("AGE", 10, 50)

notBetween

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

Sets an RdbPredicates to match the field with data type ValueType and value out of the specified range.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
field	string	Yes	Column name in the database table.
low	ValueType	Yes	Minimum value to match the RdbPredicates.
high	ValueType	Yes	Maximum value to match the RdbPredicates.

Return value

Type	Description
RdbPredicates	RdbPredicates object created.

Example

let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.notBetween("AGE", 10, 50)

greaterThan

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

Sets an RdbPredicates to match the field with data type ValueType and value greater than the specified value.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
field	string	Yes	Column name in the database table.
value	ValueType	Yes	Value to match the RdbPredicates.

Return value

Type	Description
RdbPredicates	RdbPredicates object created.

Example

let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.greaterThan("AGE", 18)

lessThan

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

Sets an RdbPredicates to match the field with data type ValueType and value less than the specified value.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
field	string	Yes	Column name in the database table.
value	ValueType	Yes	Value to match the RdbPredicates.

Return value

Type	Description
RdbPredicates	RdbPredicates object created.

Example

let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.lessThan("AGE", 20)

greaterThanOrEqualTo

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

Sets an RdbPredicates to match the field with data type ValueType and value greater than or equal to the specified value.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
field	string	Yes	Column name in the database table.
value	ValueType	Yes	Value to match the RdbPredicates.

Return value

Type	Description
RdbPredicates	RdbPredicates object created.

Example

let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.greaterThanOrEqualTo("AGE", 18)

lessThanOrEqualTo

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

Sets an RdbPredicates to match the field with data type ValueType and value less than or equal to the specified value.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
field	string	Yes	Column name in the database table.
value	ValueType	Yes	Value to match the RdbPredicates.

Return value

Type	Description
RdbPredicates	RdbPredicates object created.

Example

let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.lessThanOrEqualTo("AGE", 20)

orderByAsc

orderByAsc(field: string): RdbPredicates

Sets an RdbPredicates to match the column with values sorted in ascending order.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
field	string	Yes	Column name in the database table.

Return value

Type	Description
RdbPredicates	RdbPredicates object created.

Example

let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.orderByAsc("NAME")

orderByDesc

orderByDesc(field: string): RdbPredicates

Sets an RdbPredicates to match the column with values sorted in descending order.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
field	string	Yes	Column name in the database table.

Return value

Type	Description
RdbPredicates	RdbPredicates object created.

Example

let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.orderByDesc("AGE")

distinct

distinct(): RdbPredicates

Sets an RdbPredicates to filter out duplicate records.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Return value

Type	Description
RdbPredicates	RdbPredicates object that can filter out duplicate records.

Example

let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.equalTo("NAME", "Rose").distinct()

limitAs

limitAs(value: number): RdbPredicates

Sets an RdbPredicates to specify the maximum number of records.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
value	number	Yes	Maximum number of records.

Return value

Type	Description
RdbPredicates	RdbPredicates object that specifies the maximum number of records.

Example

let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.equalTo("NAME", "Rose").limitAs(3)

offsetAs

offsetAs(rowOffset: number): RdbPredicates

Sets an RdbPredicates to specify the start position of the returned result.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
rowOffset	number	Yes	Number of rows to offset from the beginning. The value is a positive integer.

Return value

Type	Description
RdbPredicates	RdbPredicates object that specifies the start position of the returned result.

Example

let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.equalTo("NAME", "Rose").offsetAs(3)

groupBy

groupBy(fields: Array<string>): RdbPredicates

Sets an RdbPredicates to group rows that have the same value into summary rows.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
fields	Array<string>	Yes	Names of columns to group.

Return value

Type	Description
RdbPredicates	RdbPredicates object that groups rows with the same value.

Example

let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.groupBy(["AGE", "NAME"])

indexedBy

indexedBy(field: string): RdbPredicates

Sets an RdbPredicates object to specify the index column.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
field	string	Yes	Name of the index column.

Return value

Type	Description
RdbPredicates	RdbPredicates object that specifies the index column.

Example

let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.indexedBy("SALARY_INDEX")

in

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

Sets an RdbPredicates to match the field with data type Array<ValueType> and value within the specified range.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
field	string	Yes	Column name in the database table.
value	Array<ValueType>	Yes	Array of ValueTypes to match.

Return value

Type	Description
RdbPredicates	RdbPredicates object created.

Example

let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.in("AGE", [18, 20])

notIn

notIn(field: string, value: Array<ValueType>): RdbPredicates

Sets an RdbPredicates to match the field with data type Array<ValueType> and value out of the specified range.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
field	string	Yes	Column name in the database table.
value	Array<ValueType>	Yes	Array of ValueTypes to match.

Return value

Type	Description
RdbPredicates	RdbPredicates object created.

Example

let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.notIn("NAME", ["Lisa", "Rose"])

RdbStore

Provides methods to manage an RDB store.

Before using the APIs of this class, use executeSql to initialize the database table structure and related data.

insert

insert(table: string, values: ValuesBucket, callback: AsyncCallback<number>):void

Inserts a row of data into a table. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
table	string	Yes	Name of the target table.
values	ValuesBucket	Yes	Row of data to insert.
callback	AsyncCallback<number>	Yes	Callback invoked to return the result. If the operation is successful, the row ID will be returned. Otherwise, -1 will be returned.

Example

import { ValuesBucket } from '@ohos.data.ValuesBucket';

let key1 = "NAME";
let key2 = "AGE";
let key3 = "SALARY";
let key4 = "CODES";
let value1 = "Lisi";
let value2 = 18;
let value3 = 100.5;
let value4 = new Uint8Array([1, 2, 3, 4, 5]);
const valueBucket: ValuesBucket = {
  key1: value1,
  key2: value2,
  key3: value3,
  key4: value4,
};

rdbStore.insert("EMPLOYEE", valueBucket, (status: number, rowId: number) => {
  if (status) {
    console.log("Failed to insert data");
    return;
  }
  console.log("Inserted data successfully, rowId = " + rowId);
})

insert

insert(table: string, values: ValuesBucket):Promise<number>

Inserts a row of data into a table. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
table	string	Yes	Name of the target table.
values	ValuesBucket	Yes	Row of data to insert.

Return value

Type	Description
Promise<number>	Promise used to return the result. If the operation is successful, the row ID will be returned. Otherwise, -1 will be returned.

Example

import { ValuesBucket } from '@ohos.data.ValuesBucket';

let key1 = "NAME";
let key2 = "AGE";
let key3 = "SALARY";
let key4 = "CODES";
let value1 = "Lisi";
let value2 = 18;
let value3 = 100.5;
let value4 = new Uint8Array([1, 2, 3, 4, 5]);
const valueBucket: ValuesBucket = {
  key1: value1,
  key2: value2,
  key3: value3,
  key4: value4,
};

let promise: void = rdbStore.insert("EMPLOYEE", valueBucket)
promise.then((rowId: BusinessError) => {
  console.log("Inserted data successfully, rowId = " + rowId);
}).catch((status: number) => {
  console.log("Failed to insert data");
})

batchInsert

batchInsert(table: string, values: Array<ValuesBucket>, callback: AsyncCallback<number>):void

Batch inserts data into a table. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
table	string	Yes	Name of the target table.
values	Array<ValuesBucket>	Yes	An array of data to insert.
callback	AsyncCallback<number>	Yes	Callback invoked to return the result. If the operation is successful, the number of inserted data records is returned. Otherwise, -1 is returned.

Example

import { ValuesBucket } from '@ohos.data.ValuesBucket';

let key1 = "NAME";
let key2 = "AGE";
let key3 = "SALARY";
let key4 = "CODES";
let value1 = "Lisa";
let value2 = 18;
let value3 = 100.5;
let value4 = new Uint8Array([1, 2, 3, 4, 5]);
let value5 = "Jack";
let value6 = 19;
let value7 = 101.5;
let value8 = new Uint8Array([6, 7, 8, 9, 10]);
let value9 = "Tom";
let value10 = 20;
let value11 = 102.5;
let value12 = new Uint8Array([11, 12, 13, 14, 15]);
const valueBucket1: ValuesBucket = {
  key1: value1,
  key2: value2,
  key3: value3,
  key4: value4,
};
const valueBucket2: ValuesBucket = {
  key1: value5,
  key2: value6,
  key3: value7,
  key4: value8,
};
const valueBucket3: ValuesBucket = {
  key1: value9,
  key2: value10,
  key3: value11,
  key4: value12,
};

let valueBuckets = new Array(valueBucket1, valueBucket2, valueBucket3);
rdbStore.batchInsert("EMPLOYEE", valueBuckets, (status: number, insertNum: number) => {
  if (status) {
    console.log("batchInsert is failed, status = " + status);
    return;
  }
  console.log("batchInsert is successful, the number of values that were inserted = " + insertNum);
})

batchInsert

batchInsert(table: string, values: Array<ValuesBucket>):Promise<number>

Batch inserts data into a table. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
table	string	Yes	Name of the target table.
values	Array<ValuesBucket>	Yes	An array of data to insert.

Return value

Type	Description
Promise<number>	Promise used to return the result. If the operation is successful, the number of inserted data records is returned. Otherwise, -1 is returned.

Example

import { ValuesBucket } from '@ohos.data.ValuesBucket';

let key1 = "NAME";
let key2 = "AGE";
let key3 = "SALARY";
let key4 = "CODES";
let value1 = "Lisa";
let value2 = 18;
let value3 = 100.5;
let value4 = new Uint8Array([1, 2, 3, 4, 5]);
let value5 = "Jack";
let value6 = 19;
let value7 = 101.5;
let value8 = new Uint8Array([6, 7, 8, 9, 10]);
let value9 = "Tom";
let value10 = 20;
let value11 = 102.5;
let value12 = new Uint8Array([11, 12, 13, 14, 15]);
const valueBucket1: ValuesBucket = {
  key1: value1,
  key2: value2,
  key3: value3,
  key4: value4,
};
const valueBucket2: ValuesBucket = {
  key1: value5,
  key2: value6,
  key3: value7,
  key4: value8,
};
const valueBucket3: ValuesBucket = {
  key1: value9,
  key2: value10,
  key3: value11,
  key4: value12,
};

let valueBuckets = new Array(valueBucket1, valueBucket2, valueBucket3);
let promise: void = rdbStore.batchInsert("EMPLOYEE", valueBuckets);
promise.then((insertNum: number) => {
  console.log("batchInsert is successful, the number of values that were inserted = " + insertNum);
}).catch((status: number) => {
  console.log("batchInsert is failed, status = " + status);
})

update

update(values: ValuesBucket, predicates: RdbPredicates, callback: AsyncCallback<number>):void

Updates data in the RDB store based on the specified RdbPredicates object. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
values	ValuesBucket	Yes	Rows of data to update in the RDB store. The key-value pair is associated with the column name in the target table.
predicates	RdbPredicates	Yes	Update conditions specified by the RdbPredicates object.
callback	AsyncCallback<number>	Yes	Callback invoked to return the number of rows updated.

Example

import { ValuesBucket } from '@ohos.data.ValuesBucket';

let key1 = "NAME";
let key2 = "AGE";
let key3 = "SALARY";
let key4 = "CODES";
let value1 = "Lisa";
let value2 = 18;
let value3 = 100.5;
let value4 = new Uint8Array([1, 2, 3, 4, 5]);

const valueBucket: ValuesBucket = {
  key1: value1,
  key2: value2,
  key3: value3,
  key4: value4,
};
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.equalTo("NAME", "Lisa")
rdbStore.update(valueBucket, predicates, (err: BusinessError, rows: number) => {
  if (err) {
    console.info("Failed to update data, err: " + err)
    return
  }
  console.log("Updated row count: " + rows)
})

update

update(values: ValuesBucket, predicates: RdbPredicates):Promise<number>

Updates data based on the specified RdbPredicates object. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
values	ValuesBucket	Yes	Rows of data to update in the RDB store. The key-value pair is associated with the column name in the target table.
predicates	RdbPredicates	Yes	Update conditions specified by the RdbPredicates object.

Return value

Type	Description
Promise<number>	Promise used to return the number of rows updated.

Example

import { ValuesBucket } from '@ohos.data.ValuesBucket';

let key1 = "NAME";
let key2 = "AGE";
let key3 = "SALARY";
let key4 = "CODES";
let value1 = "Lisa";
let value2 = 18;
let value3 = 100.5;
let value4 = new Uint8Array([1, 2, 3, 4, 5]);

const valueBucket: ValuesBucket = {
  key1: value1,
  key2: value2,
  key3: value3,
  key4: value4,
};
let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.equalTo("NAME", "Lisa")
let promise: void = rdbStore.update(valueBucket, predicates)
promise.then(async (rows: number) => {
  console.log("Updated row count: " + rows)
}).catch((err: BusinessError) => {
  console.info("Failed to update data, err: " + err)
})

delete

delete(predicates: RdbPredicates, callback: AsyncCallback<number>):void

Deletes data from the RDB store based on the specified RdbPredicates object. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
predicates	RdbPredicates	Yes	Conditions specified by the RdbPredicates object for deleting data.
callback	AsyncCallback<number>	Yes	Callback invoked to return the number of rows updated.

Example

let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.equalTo("NAME", "Lisa")
rdbStore.delete(predicates, (err: BusinessError, rows: number) => {
  if (err) {
    console.info("Failed to delete data, err: " + err)
    return
  }
  console.log("Deleted rows: " + rows)
})

delete

delete(predicates: RdbPredicates):Promise<number>

Deletes data from the RDB store based on the specified RdbPredicates object. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
predicates	RdbPredicates	Yes	Conditions specified by the RdbPredicates object for deleting data.

Return value

Type	Description
Promise<number>	Promise used to return the number of rows updated.

Example

let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.equalTo("NAME", "Lisa")
let promise: void = rdbStore.delete(predicates)
promise.then((rows: number) => {
  console.log("Deleted rows: " + rows)
}).catch((err: BusinessError) => {
  console.info("Failed to delete data, err: " + err)
})

query

query(predicates: RdbPredicates, columns: Array<string>, callback: AsyncCallback<ResultSet>):void

Queries data from the RDB store based on specified conditions. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
predicates	RdbPredicates	Yes	Query conditions specified by the RdbPredicates object.
columns	Array<string>	Yes	Columns to query. If this parameter is not specified, the query applies to all columns.
callback	AsyncCallback<ResultSet>	Yes	Callback invoked to return the result. If the operation is successful, a ResultSet object will be returned.

Example

let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.equalTo("NAME", "Rose")
rdbStore.query(predicates, ["ID", "NAME", "AGE", "SALARY", "CODES"], (err: BusinessError, resultSet: void) => {
  if (err) {
    console.info("Failed to query data, err: " + err)
    return
  }
  console.log("ResultSet column names: " + resultSet.columnNames)
  console.log("ResultSet column count: " + resultSet.columnCount)
})

query

query(predicates: RdbPredicates, columns?: Array<string>):Promise<ResultSet>

Queries data from the RDB store based on specified conditions. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
predicates	RdbPredicates	Yes	Query conditions specified by the RdbPredicates object.
columns	Array<string>	No	Columns to query. If this parameter is not specified, the query applies to all columns.

Return value

Type	Description
Promise<ResultSet>	Promise used to return the result. If the operation is successful, a ResultSet object will be returned.

Example

let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
predicates.equalTo("NAME", "Rose")
let promise: void = rdbStore.query(predicates, ["ID", "NAME", "AGE", "SALARY", "CODES"])
promise.then((resultSet: void) => {
  console.log("ResultSet column names: " + resultSet.columnNames)
  console.log("ResultSet column count: " + resultSet.columnCount)
}).catch((err: BusinessError) => {
  console.info("Failed to query data, err: " + err)
})

querySql⁸⁺

querySql(sql: string, bindArgs: Array<ValueType>, callback: AsyncCallback<ResultSet>):void

Queries data in the RDB store using the specified SQL statement. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
sql	string	Yes	SQL statement to run.
bindArgs	Array<ValueType>	Yes	Arguments in the SQL statement. The value corresponds to the placeholders in the SQL parameter statement. If the SQL parameter statement is complete, the value of this parameter must be an empty array.
callback	AsyncCallback<ResultSet>	Yes	Callback invoked to return the result. If the operation is successful, a ResultSet object will be returned.

Example

rdbStore.querySql("SELECT * FROM EMPLOYEE CROSS JOIN BOOK WHERE BOOK.NAME = ?", ['sanguo'], (err: BusinessError, resultSet: void) => {
  if (err) {
    console.info("Failed to query data, err: " + err)
    return
  }
  console.log("ResultSet column names: " + resultSet.columnNames)
  console.log("ResultSet column count: " + resultSet.columnCount)
})

querySql⁸⁺

querySql(sql: string, bindArgs?: Array<ValueType>):Promise<ResultSet>

Queries data using the specified SQL statement. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
sql	string	Yes	SQL statement to run.
bindArgs	Array<ValueType>	No	Arguments in the SQL statement. The value corresponds to the placeholders in the SQL parameter statement. If the SQL parameter statement is complete, leave this parameter blank.

Return value

Type	Description
Promise<ResultSet>	Promise used to return the result. If the operation is successful, a ResultSet object will be returned.

Example

let promise: void = rdbStore.querySql("SELECT * FROM EMPLOYEE CROSS JOIN BOOK WHERE BOOK.NAME = 'sanguo'")
promise.then((resultSet: void) => {
  console.log("ResultSet column names: " + resultSet.columnNames)
  console.log("ResultSet column count: " + resultSet.columnCount)
}).catch((err: BusinessError) => {
  console.info("Failed to query data, err: " + err)
})

executeSql⁸⁺

executeSql(sql: string, bindArgs: Array<ValueType>, callback: AsyncCallback<void>):void

Executes an SQL statement that contains specified arguments but returns no value. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
sql	string	Yes	SQL statement to run.
bindArgs	Array<ValueType>	Yes	Arguments in the SQL statement. The value corresponds to the placeholders in the SQL parameter statement. If the SQL parameter statement is complete, the value of this parameter must be an empty array.
callback	AsyncCallback<void>	Yes	Callback invoked to return the result.

Example

const SQL_DELETE_TABLE = "DELETE FROM test WHERE name = ?"
rdbStore.executeSql(SQL_DELETE_TABLE, ['zhangsan'], (err: BusinessError) => {
  if (err) {
    console.info("Failed to execute SQL, err: " + err)
    return
  }
  console.info('Delete table done.')
})

executeSql⁸⁺

executeSql(sql: string, bindArgs?: Array<ValueType>):Promise<void>

Executes an SQL statement that contains specified arguments but returns no value. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
sql	string	Yes	SQL statement to run.
bindArgs	Array<ValueType>	No	Arguments in the SQL statement. The value corresponds to the placeholders in the SQL parameter statement. If the SQL parameter statement is complete, leave this parameter blank.

Return value

Type	Description
Promise<void>	Promise that returns no value.

Example

const SQL_DELETE_TABLE = "DELETE FROM test WHERE name = 'zhangsan'"
let promise: void = rdbStore.executeSql(SQL_DELETE_TABLE)
promise.then(() => {
  console.info('Delete table done.')
}).catch((err: BusinessError) => {
  console.info("Failed to execute SQL, err: " + err)
})

beginTransaction⁸⁺

beginTransaction():void

Starts the transaction before executing an SQL statement.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Example

import featureAbility from '@ohos.ability.featureAbility';
import { ValuesBucket } from '@ohos.data.ValuesBucket';

let key1 = "NAME";
let key2 = "AGE";
let key3 = "SALARY";
let key4 = "blobType";
let value1 = "Lisa";
let value2 = 18;
let value3 = 100.5;
let value4 = new Uint8Array([1, 2, 3]);

const valueBucket: ValuesBucket = {
  key1: value1,
  key2: value2,
  key3: value3,
  key4: value4,
};

data_rdb.getRdbStore(this.context, "RdbTest.db", 1, async (err: BusinessError, rdbStore) => {
  rdbStore.beginTransaction()
  await rdbStore.insert("test", valueBucket)
  rdbStore.commit()
})

commit⁸⁺

commit():void

Commits the executed SQL statements.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Example

import { ValuesBucket } from '@ohos.data.ValuesBucket';
import featureAbility from '@ohos.ability.featureAbility';

let key1 = "NAME";
let key2 = "AGE";
let key3 = "SALARY";
let key4 = "blobType";
let value1 = "Lisa";
let value2 = 18;
let value3 = 100.5;
let value4 = new Uint8Array([1, 2, 3]);

const valueBucket: ValuesBucket = {
  key1: value1,
  key2: value2,
  key3: value3,
  key4: value4,
};

data_rdb.getRdbStore(this.context, "RdbTest.db", 1, async (err: BusinessError, rdbStore) => {
  rdbStore.beginTransaction()
  await rdbStore.insert("test", valueBucket)
  rdbStore.commit()
})

rollBack⁸⁺

rollBack():void

Rolls back the SQL statements that have been executed.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Example

import { ValuesBucket } from '@ohos.data.ValuesBucket';
import featureAbility from '@ohos.ability.featureAbility';

let key1 = "NAME";
let key2 = "AGE";
let key3 = "SALARY";
let key4 = "blobType";
let value1 = "Lisa";
let value2 = 18;
let value3 = 100.5;
let value4 = new Uint8Array([1, 2, 3]);

const valueBucket: ValuesBucket = {
  key1: value1,
  key2: value2,
  key3: value3,
  key4: value4,
};

const STORE_CONFIG = { name: "RdbTest.db"}
data_rdb.getRdbStore(this,context, "RdbTest.db", 1, async (err: BusinessError, rdbStore) => {
    try {
		rdbStore.beginTransaction()
		await rdbStore.insert("test", valueBucket)
		rdbStore.commit()
	} catch (e) {
		rdbStore.rollBack()
	}
})

setDistributedTables⁸⁺

setDistributedTables(tables: Array<string>, callback: AsyncCallback<void>): void

Sets distributed tables. This API uses an asynchronous callback to return the result.

Required permissions: ohos.permission.DISTRIBUTED_DATASYNC

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
tables	Array<string>	Yes	Names of the distributed tables to set.
callback	AsyncCallback<void>	Yes	Callback invoked to return the result.

Example

rdbStore.setDistributedTables(["EMPLOYEE"], (err: BusinessError) => {
  if (err) {
    console.info('Failed to set distributed tables, err: ' + err)
    return
  }
  console.info('Set distributed tables successfully.')
})

setDistributedTables⁸⁺

setDistributedTables(tables: Array<string>): Promise<void>

Sets distributed tables. This API uses a promise to return the result.

Required permissions: ohos.permission.DISTRIBUTED_DATASYNC

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
tables	Array<string>	Yes	Names of the distributed tables to set.

Return value

Type	Description
Promise<void>	Promise that returns no value.

Example

let promise: void = rdbStore.setDistributedTables(["EMPLOYEE"])
promise.then(() => {
  console.info("Set distributed tables successfully.")
}).catch((err: BusinessError) => {
  console.info("Failed to set distributed tables, err: " + err)
})

obtainDistributedTableName⁸⁺

obtainDistributedTableName(device: string, table: string, callback: AsyncCallback<string>): void

Obtains the distributed table name of a remote device based on the local table name of the device. The distributed table name is required when the RDB store of a remote device is queried.

NOTE

The value of device 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.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
device	string	Yes	ID of the remote device.
table	string	Yes	Local table name of the remote device.
callback	AsyncCallback<string>	Yes	Callback invoked to return the result. If the operation succeeds, the distributed table name of the remote device is returned.

Example

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

let dmInstance: Array<string>;

deviceManager.createDeviceManager("com.example.appdatamgrverify", (err: BusinessError, manager: void) => {
  if (err) {
    console.log("create device manager failed, err=" + err);
    return;
  }
  dmInstance = manager;
  let devices: Array<string> = dmInstance.getTrustedDeviceListSync();
  let deviceId: Array<string> = devices[0].deviceId;
})

rdbStore.obtainDistributedTableName(deviceId, "EMPLOYEE", (err: BusinessError, tableName: String) {
  if (err) {
    console.info('Failed to obtain DistributedTableName, err: ' + err)
    return
  }
  console.info('Obtained distributed table name successfully, tableName=.' + tableName)
})

obtainDistributedTableName⁸⁺

obtainDistributedTableName(device: string, table: string): Promise<string>

Obtains the distributed table name of a remote device based on the local table name of the device. The distributed table name is required when the RDB store of a remote device is queried.

NOTE

The value of device 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.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
device	string	Yes	ID of the remote device.
table	string	Yes	Local table name of the remote device.

Return value

Type	Description
Promise<string>	Promise used to return the result. If the operation succeeds, the distributed table name of the remote device is returned.

Example

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

let dmInstance: Array<string>;

deviceManager.createDeviceManager("com.example.appdatamgrverify", (err: BusinessError, manager: void) => {
  if (err) {
    console.log("create device manager failed, err=" + err);
    return;
  }
  dmInstance = manager;
  let devices: Array<string> = dmInstance.getTrustedDeviceListSync();
  let deviceId: Array<string> = devices[0].deviceId;
})

let promise: void = rdbStore.obtainDistributedTableName(deviceId, "EMPLOYEE")
promise.then((tableName: String) => {
  console.info('Obtained distributed table name successfully, tableName= ' + tableName)
}).catch((err: BusinessError) => {
  console.info('Failed to obtain DistributedTableName, err: ' + err)
})

sync⁸⁺

sync(mode: SyncMode, predicates: RdbPredicates, callback: AsyncCallback<Array<[string, number]>>): void

Synchronizes data between devices. This API uses an asynchronous callback to return the result.

Required permissions: ohos.permission.DISTRIBUTED_DATASYNC

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
mode	SyncMode	Yes	Data synchronization mode. The value can be push or pull.
predicates	RdbPredicates	Yes	RdbPredicates object that specifies the data and devices to synchronize.
callback	AsyncCallback<Array<[string, number]>>	Yes	Callback invoked to send the synchronization result to the caller. string indicates the device ID. number indicates the synchronization status of that device. The value 0 indicates a successful synchronization. Other values indicate a synchronization failure.

Example

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

let dmInstance: Array<string>;

deviceManager.createDeviceManager("com.example.appdatamgrverify", (err: BusinessError, manager: void) => {
  if (err) {
    console.log("create device manager failed, err=" + err);
    return;
  }
  dmInstance = manager;
  let devices: Array<string> = dmInstance.getTrustedDeviceListSync();
  for (let i = 0; i < devices.length; i++) {
    let deviceIds: Array<string> = devices[i].deviceId;
  }
})

let predicates = new data_rdb.RdbPredicates('EMPLOYEE')
predicates.inDevices(deviceIds)
rdbStore.sync(data_rdb.SyncMode.SYNC_MODE_PUSH, predicates, (err: BusinessError, result: void) {
  if (err) {
    console.log('Sync failed, err: ' + err)
    return
  }
  console.log('Sync done.')
  for (let i = 0; i < result.length; i++) {
    console.log('device=' + result[i][0] + ' status=' + result[i][1])
  }
})

sync⁸⁺

sync(mode: SyncMode, predicates: RdbPredicates): Promise<Array<[string, number]>>

Synchronizes data between devices. This API uses a promise to return the result.

Required permissions: ohos.permission.DISTRIBUTED_DATASYNC

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
mode	SyncMode	Yes	Data synchronization mode. The value can be push or pull.
predicates	RdbPredicates	Yes	RdbPredicates object that specifies the data and devices to synchronize.

Return value

Type	Description
Promise<Array<[string, number]>>	Promise used to send the synchronization result. string indicates the device ID. number indicates the synchronization status of that device. The value 0 indicates a successful synchronization. Other values indicate a synchronization failure.

Example

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

let dmInstance: Array<string>;

deviceManager.createDeviceManager("com.example.appdatamgrverify", (err: BusinessError, manager: void) => {
  if (err) {
    console.log("create device manager failed, err=" + err);
    return;
  }
  dmInstance = manager;
  let devices: Array<string> = dmInstance.getTrustedDeviceListSync();
  for (let i = 0; i < devices.length; i++) {
    let deviceIds: Array<string> = devices[i].deviceId;
  }
})

let predicates = new data_rdb.RdbPredicates('EMPLOYEE')
predicates.inDevices(deviceIds)
let promise: void = rdbStore.sync(data_rdb.SyncMode.SYNC_MODE_PUSH, predicates)
promise.then((result: void) =>{
  console.log('Sync done.')
  for (let i = 0; i < result.length; i++) {
    console.log('device=' + result[i][0] + ' status=' + result[i][1])
  }
}).catch((err: BusinessError) => {
  console.log('Sync failed')
})

on(‘dataChange’)⁸⁺

on(event: ‘dataChange’, type: SubscribeType, observer: Callback<Array<string>>): void

Registers an observer for this RDB store. When the data in the RDB store changes, a callback is invoked to return the data changes.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
event	string	Yes	Event type. The value is ‘dataChange’, which indicates data changes.
type	SubscribeType	Yes	Subscription type to register.
observer	Callback<Array<string>>	Yes	Observer that listens for the data changes in the RDB store. Array indicates the ID of the peer device whose data in the database is changed.

Example

let devices: Array<string>;

try {
  rdbStore.on('dataChange', data_rdb.SubscribeType.SUBSCRIBE_TYPE_REMOTE, (storeObserver: Array<string>) => {
    for (let i = 0; i < devices.length; i++) {
      console.log('device=' + devices[i] + ' data changed')
    }
  })
} catch (err) {
  console.log('Failed to register observer')
}

off(‘dataChange’)⁸⁺

off(event:‘dataChange’, type: SubscribeType, observer: Callback<Array<string>>): void

Unregisters the observer of the specified type from the RDB store. This API uses a callback to return the result.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Name	Type	Mandatory	Description
event	string	Yes	Event type. The value is ‘dataChange’, which indicates data changes.
type	SubscribeType	Yes	Subscription type to unregister.
observer	Callback<Array<string>>	Yes	Data change observer to unregister. Array indicates the ID of the peer device whose data in the database is changed.

Example

let devices: Array<string>;

try {
  rdbStore.off('dataChange', data_rdb.SubscribeType.SUBSCRIBE_TYPE_REMOTE, (storeObserver: Array<string>) => {
    for (let i = 0; i < devices.length; i++) {
      console.log('device=' + devices[i] + ' data changed')
    }
  })
} catch (err) {
  console.log('Failed to unregister observer')
}

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harmony 鸿蒙@ohos.data.rdb (RDB)

@ohos.data.rdb (RDB)

Modules to Import

data_rdb.getRdbStore

data_rdb.getRdbStore

data_rdb.deleteRdbStore

data_rdb.deleteRdbStore

ValueType

ValuesBucket

SyncMode8+

SubscribeType8+

StoreConfig

RdbPredicates

constructor

inDevices8+

inAllDevices8+

equalTo

notEqualTo

beginWrap

endWrap

or

and

contains

beginsWith

endsWith

isNull

isNotNull

like

glob

between

notBetween

greaterThan

lessThan

greaterThanOrEqualTo

lessThanOrEqualTo

orderByAsc

orderByDesc

distinct

limitAs

offsetAs

groupBy

indexedBy

in

notIn

RdbStore

insert

insert

batchInsert

batchInsert

update

update

delete

delete

query

query

querySql8+

querySql8+

executeSql8+

executeSql8+

beginTransaction8+

commit8+

rollBack8+

setDistributedTables8+

setDistributedTables8+

obtainDistributedTableName8+

obtainDistributedTableName8+

sync8+

sync8+

on(‘dataChange’)8+

off(‘dataChange’)8+

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本文目录

SyncMode⁸⁺

SubscribeType⁸⁺

inDevices⁸⁺

inAllDevices⁸⁺

querySql⁸⁺

querySql⁸⁺

executeSql⁸⁺

executeSql⁸⁺

beginTransaction⁸⁺

commit⁸⁺

rollBack⁸⁺

setDistributedTables⁸⁺

setDistributedTables⁸⁺

obtainDistributedTableName⁸⁺

obtainDistributedTableName⁸⁺

sync⁸⁺

sync⁸⁺

on(‘dataChange’)⁸⁺

off(‘dataChange’)⁸⁺