@ohos.data.relationalStore (RDB Store)

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

The relationalStore module provides the following 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 data in an RDB store.
• ResultSet: provides APIs for accessing the result set obtained from the RDB store.

NOTE

The initial APIs of this module are supported since API version 9. Newly added APIs will be marked with a superscript to indicate their earliest API version.

Modules to Import

import relationalStore from '@ohos.data.relationalStore'

relationalStore.getRdbStore

getRdbStore(context: Context, config: StoreConfig, 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

Error codes

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

Example

FA model:

import featureAbility from '@ohos.ability.featureAbility'

var store;

// Obtain the context.
let context = featureAbility.getContext();

const STORE_CONFIG = {
  name: "RdbTest.db",
  securityLevel: relationalStore.SecurityLevel.S1
};

relationalStore.getRdbStore(context, STORE_CONFIG, function (err, rdbStore) {
  store = rdbStore;
  if (err) {
    console.error(`Get RdbStore failed, err: ${err}`);
    return;
  }
  console.info(`Get RdbStore successfully.`);
})

Stage model:

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

class EntryAbility extends UIAbility {
  onWindowStageCreate(windowStage) {
    var store;
    const STORE_CONFIG = {
      name: "RdbTest.db",
      securityLevel: relationalStore.SecurityLevel.S1
    };
        
    relationalStore.getRdbStore(this.context, STORE_CONFIG, function (err, rdbStore) {
      store = rdbStore;
      if (err) {
        console.error(`Get RdbStore failed, err: ${err}`);
        return;
      }
      console.info(`Get RdbStore successfully.`);
    })
  }
}

relationalStore.getRdbStore

getRdbStore(context: Context, config: StoreConfig): 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

Return value

Error codes

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

Example

FA model:

import featureAbility from '@ohos.ability.featureAbility'

var store;

// Obtain the context.
let context = featureAbility.getContext();

const STORE_CONFIG = {
  name: "RdbTest.db",
  securityLevel: relationalStore.SecurityLevel.S1
};

let promise = relationalStore.getRdbStore(context, STORE_CONFIG);
promise.then(async (rdbStore) => {
  store = rdbStore;
  console.info(`Get RdbStore successfully.`);
}).catch((err) => {
  console.error(`Get RdbStore failed, err: ${err}`);
})

Stage model:

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

class EntryAbility extends UIAbility {
  onWindowStageCreate(windowStage) {
    var store;
    const STORE_CONFIG = {
      name: "RdbTest.db",
      securityLevel: relationalStore.SecurityLevel.S1
    };
        
    let promise = relationalStore.getRdbStore(this.context, STORE_CONFIG);
    promise.then(async (rdbStore) => {
      store = rdbStore;
      console.info(`Get RdbStore successfully.`)
    }).catch((err) => {
      console.error(`Get RdbStore failed, err: ${err}`);
    })
  }
}

relationalStore.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

Error codes

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

Example

FA model:

import featureAbility from '@ohos.ability.featureAbility'

// Obtain the context.
let context = featureAbility.getContext()

relationalStore.deleteRdbStore(context, "RdbTest.db", function (err) {
  if (err) {
    console.error(`Delete RdbStore failed, err: ${err}`);
    return;
  }
  console.info(`Delete RdbStore successfully.`);
})

Stage model:

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

class EntryAbility extends UIAbility {
  onWindowStageCreate(windowStage){
    relationalStore.deleteRdbStore(this.context, "RdbTest.db", function (err) {
      if (err) {
        console.error(`Delete RdbStore failed, err: ${err}`);
        return;
      }
      console.info(`Delete RdbStore successfully.`);
    })
  }
}

relationalStore.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

Return value

Error codes

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

Example

FA model:

import featureAbility from '@ohos.ability.featureAbility'

// Obtain the context.
let context = featureAbility.getContext();

let promise = relationalStore.deleteRdbStore(context, "RdbTest.db");
promise.then(()=>{
  console.info(`Delete RdbStore successfully.`);
}).catch((err) => {
  console.error(`Delete RdbStore failed, err: ${err}`);
})

Stage model:

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

class EntryAbility extends UIAbility {
  onWindowStageCreate(windowStage){
    let promise = relationalStore.deleteRdbStore(this.context, "RdbTest.db");
    promise.then(()=>{
      console.info(`Delete RdbStore successfully.`);
    }).catch((err) => {
      console.error(`Delete RdbStore failed, err: ${err}`);
    })
  }
}

StoreConfig

Defines the RDB store configuration.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

SecurityLevel

Enumerates the RDB store security levels.

NOTE

To perform data synchronization operations, the RDB store security level must be lower than or equal to that of the peer device. For details, see the Cross-Device Data Synchronization Mechanism.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

ValueType

Defines the data types allowed.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

ValuesBucket

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

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

SyncMode

Defines the database synchronization mode.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

SubscribeType

Defines the subscription type.

Required permissions: ohos.permission.DISTRIBUTED_DATASYNC

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

RdbPredicates

Defines the 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

Example

let predicates = new relationalStore.RdbPredicates("EMPLOYEE");

inDevices

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

Return value

Example

import deviceManager from '@ohos.distributedHardware.deviceManager';
let dmInstance = null;
let deviceIds = [];

deviceManager.createDeviceManager("com.example.appdatamgrverify", (err, manager) => {
    if (err) {
        console.log("create device manager failed, err=" + err);
        return;
    }
    dmInstance = manager;
    let devices = dmInstance.getTrustedDeviceListSync();
    for (var i = 0; i < devices.length; i++) {
        deviceIds[i] = devices[i].deviceId;
    }
})
                                  
let predicates = new relationalStore.RdbPredicates("EMPLOYEE");
predicates.inDevices(deviceIds);

inAllDevices

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

Example

let predicates = new relationalStore.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

Return value

Example

let predicates = new relationalStore.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

Return value

Example

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

beginWrap

beginWrap(): RdbPredicates

Adds a left parenthesis to the RdbPredicates.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Return value

Example

let predicates = new relationalStore.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

Example

let predicates = new relationalStore.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

Example

let predicates = new relationalStore.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

Example

let predicates = new relationalStore.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

Return value

Example

let predicates = new relationalStore.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

Return value

Example

let predicates = new relationalStore.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

Return value

Example

let predicates = new relationalStore.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

Return value

Example

let predicates = new relationalStore.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

Return value

Example

let predicates = new relationalStore.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

Return value

Example

let predicates = new relationalStore.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

Return value

Example

let predicates = new relationalStore.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

Return value

Example

let predicates = new relationalStore.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

Return value

Example

let predicates = new relationalStore.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

Return value

Example

let predicates = new relationalStore.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

Return value

Example

let predicates = new relationalStore.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

Return value

Example

let predicates = new relationalStore.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

Return value

Example

let predicates = new relationalStore.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

Return value

Example

let predicates = new relationalStore.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

Return value

Example

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

distinct

distinct(): RdbPredicates

Sets an RdbPredicates to filter out duplicate records.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Return value

Example

let predicates = new relationalStore.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

Return value

Example

let predicates = new relationalStore.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

Return value

Example

let predicates = new relationalStore.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

Return value

Example

let predicates = new relationalStore.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

Return value

Example

let predicates = new relationalStore.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

Return value

Example

let predicates = new relationalStore.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

Return value

Example

let predicates = new relationalStore.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

Example

const valueBucket = {
  "NAME": "Lisa",
  "AGE": 18,
  "SALARY": 100.5,
  "CODES": new Uint8Array([1, 2, 3, 4, 5]),
};
store.insert("EMPLOYEE", valueBucket, function (err, rowId) {
  if (err) {
    console.error(`Insert is failed, err: ${err}`);
    return;
  }
  console.info(`Insert is successful, 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

Return value

Example

const valueBucket = {
  "NAME": "Lisa",
  "AGE": 18,
  "SALARY": 100.5,
  "CODES": new Uint8Array([1, 2, 3, 4, 5]),
};
let promise = store.insert("EMPLOYEE", valueBucket);
promise.then((rowId) => {
  console.info(`Insert is successful, rowId = ${rowId}`);
}).catch((err) => {
  console.error(`Insert is failed, err: ${err}`);
})

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

Example

const valueBucket1 = {
  "NAME": "Lisa",
  "AGE": 18,
  "SALARY": 100.5,
  "CODES": new Uint8Array([1, 2, 3, 4, 5])
};
const valueBucket2 = {
  "NAME": "Jack",
  "AGE": 19,
  "SALARY": 101.5,
  "CODES": new Uint8Array([6, 7, 8, 9, 10])
};
const valueBucket3 = {
  "NAME": "Tom",
  "AGE": 20,
  "SALARY": 102.5,
  "CODES": new Uint8Array([11, 12, 13, 14, 15])
};

let valueBuckets = new Array(valueBucket1, valueBucket2, valueBucket3);
store.batchInsert("EMPLOYEE", valueBuckets, function(err, insertNum) {
  if (err) {
    console.error(`batchInsert is failed, err: ${err}`);
    return;
  }
  console.info(`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

Return value

Example

const valueBucket1 = {
  "NAME": "Lisa",
  "AGE": 18,
  "SALARY": 100.5,
  "CODES": new Uint8Array([1, 2, 3, 4, 5])
};
const valueBucket2 = {
  "NAME": "Jack",
  "AGE": 19,
  "SALARY": 101.5,
  "CODES": new Uint8Array([6, 7, 8, 9, 10])
};
const valueBucket3 = {
  "NAME": "Tom",
  "AGE": 20,
  "SALARY": 102.5,
  "CODES": new Uint8Array([11, 12, 13, 14, 15])
};

let valueBuckets = new Array(valueBucket1, valueBucket2, valueBucket3);
let promise = store.batchInsert("EMPLOYEE", valueBuckets);
promise.then((insertNum) => {
  console.info(`batchInsert is successful, the number of values that were inserted = ${insertNum}`);
}).catch((err) => {
  console.error(`batchInsert is failed, err: ${err}`);
})

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

Example

const valueBucket = {
  "NAME": "Rose",
  "AGE": 22,
  "SALARY": 200.5,
  "CODES": new Uint8Array([1, 2, 3, 4, 5]),
};
let predicates = new relationalStore.RdbPredicates("EMPLOYEE");
predicates.equalTo("NAME", "Lisa");
store.update(valueBucket, predicates, function (err, rows) {
  if (err) {
    console.error(`Updated failed, err: ${err}`);
    return;
  }
  console.info(`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

Return value

Example

const valueBucket = {
  "NAME": "Rose",
  "AGE": 22,
  "SALARY": 200.5,
  "CODES": new Uint8Array([1, 2, 3, 4, 5]),
};
let predicates = new relationalStore.RdbPredicates("EMPLOYEE");
predicates.equalTo("NAME", "Lisa");
let promise = store.update(valueBucket, predicates);
promise.then(async (rows) => {
  console.info(`Updated row count: ${rows}`);
}).catch((err) => {
  console.error(`Updated failed, err: ${err}`);
})

update

update(table: string, values: ValuesBucket, predicates: dataSharePredicates.DataSharePredicates, callback: AsyncCallback<number>):void

Updates data based on the specified DataSharePredicates object. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

System API: This is a system API.

Parameters

Example

import dataSharePredicates from '@ohos.data.dataSharePredicates'
const valueBucket = {
    "NAME": "Rose",
    "AGE": 22,
    "SALARY": 200.5,
    "CODES": new Uint8Array([1, 2, 3, 4, 5]),
};
let predicates = new dataSharePredicates.DataSharePredicates();
predicates.equalTo("NAME", "Lisa");
store.update("EMPLOYEE", valueBucket, predicates, function (err, rows) {
  if (err) {
    console.error(`Updated failed, err: ${err}`);
    return;
  }
  console.info(`Updated row count: ${rows}`);
})

update

update(table: string, values: ValuesBucket, predicates: dataSharePredicates.DataSharePredicates):Promise<number>

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

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

System API: This is a system API.

Parameters

Return value

Example

import dataSharePredicates from '@ohos.data.dataSharePredicates'
const valueBucket = {
  "NAME": "Rose",
  "AGE": 22,
  "SALARY": 200.5,
  "CODES": new Uint8Array([1, 2, 3, 4, 5]),
};
let predicates = new dataSharePredicates.DataSharePredicates();
predicates.equalTo("NAME", "Lisa");
let promise = store.update("EMPLOYEE", valueBucket, predicates);
promise.then(async (rows) => {
  console.info(`Updated row count: ${rows}`);
}).catch((err) => {
  console.error(`Updated failed, 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

Example

let predicates = new relationalStore.RdbPredicates("EMPLOYEE");
predicates.equalTo("NAME", "Lisa");
store.delete(predicates, function (err, rows) {
  if (err) {
    console.error(`Delete failed, err: ${err}`);
    return;
  }
  console.info(`Delete 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

Return value

Example

let predicates = new relationalStore.RdbPredicates("EMPLOYEE");
predicates.equalTo("NAME", "Lisa");
let promise = store.delete(predicates);
promise.then((rows) => {
  console.info(`Delete rows: ${rows}`);
}).catch((err) => {
  console.error(`Delete failed, err: ${err}`);
})

delete

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

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

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

System API: This is a system API.

Parameters

Example

import dataSharePredicates from '@ohos.data.dataSharePredicates'
let predicates = new dataSharePredicates.DataSharePredicates();
predicates.equalTo("NAME", "Lisa");
store.delete("EMPLOYEE", predicates, function (err, rows) {
  if (err) {
    console.error(`Delete failed, err: ${err}`);
    return;
  }
  console.info(`Delete rows: ${rows}`);
})

delete

delete(table: string, predicates: dataSharePredicates.DataSharePredicates):Promise<number>

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

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

System API: This is a system API.

Parameters

Return value

Example

import dataSharePredicates from '@ohos.data.dataSharePredicates'
let predicates = new dataSharePredicates.DataSharePredicates();
predicates.equalTo("NAME", "Lisa");
let promise = store.delete("EMPLOYEE", predicates);
promise.then((rows) => {
  console.info(`Delete rows: ${rows}`);
}).catch((err) => {
  console.error(`Delete failed, 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

Example

let predicates = new relationalStore.RdbPredicates("EMPLOYEE");
predicates.equalTo("NAME", "Rose");
store.query(predicates, ["ID", "NAME", "AGE", "SALARY", "CODES"], function (err, resultSet) {
  if (err) {
    console.error(`Query failed, err: ${err}`);
    return;
  }
  console.info(`ResultSet column names: ${resultSet.columnNames}`);
  console.info(`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

Return value

Example

let predicates = new relationalStore.RdbPredicates("EMPLOYEE");
predicates.equalTo("NAME", "Rose");
let promise = store.query(predicates, ["ID", "NAME", "AGE", "SALARY", "CODES"]);
promise.then((resultSet) => {
console.info(`ResultSet column names: ${resultSet.columnNames}`);
console.info(`ResultSet column count: ${resultSet.columnCount}`);
}).catch((err) => {
console.error(`Query failed, err: ${err}`);
})

query

query(table: string, predicates: dataSharePredicates.DataSharePredicates, 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

System API: This is a system API.

Parameters

Example

import dataSharePredicates from '@ohos.data.dataSharePredicates'
let predicates = new dataSharePredicates.DataSharePredicates();
predicates.equalTo("NAME", "Rose");
store.query("EMPLOYEE", predicates, ["ID", "NAME", "AGE", "SALARY", "CODES"], function (err, resultSet) {
  if (err) {
    console.error(`Query failed, err: ${err}`);
    return;
  }
  console.info(`ResultSet column names: ${resultSet.columnNames}`);
  console.info(`ResultSet column count: ${resultSet.columnCount}`);
})

query

query(table: string, predicates: dataSharePredicates.DataSharePredicates, 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

System API: This is a system API.

Parameters

Return value

Example

import dataSharePredicates from '@ohos.data.dataSharePredicates'
let predicates = new dataSharePredicates.DataSharePredicates();
predicates.equalTo("NAME", "Rose");
let promise = store.query("EMPLOYEE", predicates, ["ID", "NAME", "AGE", "SALARY", "CODES"]);
promise.then((resultSet) => {
  console.info(`ResultSet column names: ${resultSet.columnNames}`);
  console.info(`ResultSet column count: ${resultSet.columnCount}`);
}).catch((err) => {
  console.error(`Query failed, err: ${err}`);
})

remoteQuery

remoteQuery(device: string, table: string, predicates: RdbPredicates, columns: Array<string> , callback: AsyncCallback<ResultSet>): void

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

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.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Example

import deviceManager from '@ohos.distributedHardware.deviceManager';
let dmInstance = null;
let deviceId = null;

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

let predicates = new relationalStore.RdbPredicates('EMPLOYEE');
predicates.greaterThan("id", 0);
store.remoteQuery(deviceId, "EMPLOYEE", predicates, ["ID", "NAME", "AGE", "SALARY", "CODES"],
  function(err, resultSet) {
    if (err) {
      console.error(`Failed to remoteQuery, err: ${err}`);
      return;
    }
    console.info(`ResultSet column names: ${resultSet.columnNames}`);
    console.info(`ResultSet column count: ${resultSet.columnCount}`);
  }
)

remoteQuery

remoteQuery(device: string, table: string, predicates: RdbPredicates, columns: Array<string>): Promise<ResultSet>

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

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.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Return value

Example

import deviceManager from '@ohos.distributedHardware.deviceManager';
let dmInstance = null;
let deviceId = null;

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

let predicates = new relationalStore.RdbPredicates('EMPLOYEE');
predicates.greaterThan("id", 0);
let promise = store.remoteQuery(deviceId, "EMPLOYEE", predicates, ["ID", "NAME", "AGE", "SALARY", "CODES"]);
promise.then((resultSet) => {
  console.info(`ResultSet column names: ${resultSet.columnNames}`);
  console.info(`ResultSet column count: ${resultSet.columnCount}`);
}).catch((err) => {
  console.error(`Failed to remoteQuery, err: ${err}`);
})

querySql

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

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

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Example

store.querySql("SELECT * FROM EMPLOYEE CROSS JOIN BOOK WHERE BOOK.NAME = ?", ['sanguo'], function (err, resultSet) {
  if (err) {
    console.error(`Query failed, err: ${err}`);
    return;
  }
  console.info(`ResultSet column names: ${resultSet.columnNames}`);
  console.info(`ResultSet column count: ${resultSet.columnCount}`);
})

querySql

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

Return value

Example

let promise = store.querySql("SELECT * FROM EMPLOYEE CROSS JOIN BOOK WHERE BOOK.NAME = 'sanguo'");
promise.then((resultSet) => {
  console.info(`ResultSet column names: ${resultSet.columnNames}`);
  console.info(`ResultSet column count: ${resultSet.columnCount}`);
}).catch((err) => {
  console.error(`Query failed, err: ${err}`);
})

executeSql

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

Example

const SQL_DELETE_TABLE = "DELETE FROM test WHERE name = ?"
store.executeSql(SQL_DELETE_TABLE, ['zhangsan'], function(err) {
  if (err) {
    console.error(`ExecuteSql failed, err: ${err}`);
    return;
  }
  console.info(`Delete table done.`);
})

executeSql

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

Return value

Example

const SQL_DELETE_TABLE = "DELETE FROM test WHERE name = 'zhangsan'"
let promise = store.executeSql(SQL_DELETE_TABLE);
promise.then(() => {
    console.info(`Delete table done.`);
}).catch((err) => {
    console.error(`ExecuteSql failed, err: ${err}`);
})

beginTransaction

beginTransaction():void

Starts the transaction before executing an SQL statement.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Example

import featureAbility from '@ohos.ability.featureAbility'
let context = featureAbility.getContext();
const STORE_CONFIG = { 
  name: "RdbTest.db",
  securityLevel: relationalStore.SecurityLevel.S1
};
relationalStore.getRdbStore(context, STORE_CONFIG, async function (err, store) {
  if (err) {
    console.error(`GetRdbStore failed, err: ${err}`);
    return;
  }
  store.beginTransaction();
  const valueBucket = {
    "name": "lisi",
	"age": 18,
	"salary": 100.5,
	"blobType": new Uint8Array([1, 2, 3]),
  };
  await store.insert("test", valueBucket);
  store.commit();
})

commit

commit():void

Commits the executed SQL statements.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Example

import featureAbility from '@ohos.ability.featureAbility'
let context = featureAbility.getContext();
const STORE_CONFIG = { 
  name: "RdbTest.db",
  securityLevel: relationalStore.SecurityLevel.S1
};
relationalStore.getRdbStore(context, STORE_CONFIG, async function (err, store) {
  if (err) {
     console.error(`GetRdbStore failed, err: ${err}`);
     return;
  }
  store.beginTransaction();
  const valueBucket = {
	"name": "lisi",
	"age": 18,
	"salary": 100.5,
	"blobType": new Uint8Array([1, 2, 3]),
  };
  await store.insert("test", valueBucket);
  store.commit();
})

rollBack

rollBack():void

Rolls back the SQL statements that have been executed.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Example

import featureAbility from '@ohos.ability.featureAbility'
let context = featureAbility.getContext();
const STORE_CONFIG = { 
  name: "RdbTest.db",
  securityLevel: relationalStore.SecurityLevel.S1
};
relationalStore.getRdbStore(context, STORE_CONFIG, async function (err, store) {
  if (err) {
    console.error(`GetRdbStore failed, err: ${err}`);
    return;
  }
  try {
    store.beginTransaction()
    const valueBucket = {
	  "id": 1,
	  "name": "lisi",
	  "age": 18,
	  "salary": 100.5,
	  "blobType": new Uint8Array([1, 2, 3]),
	};
	await store.insert("test", valueBucket);
    store.commit();
  } catch (err) {
    console.error(`Transaction failed, err: ${err}`);
    store.rollBack();
  }
})

backup

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

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

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Example

store.backup("dbBackup.db", function(err) {
  if (err) {
    console.error(`Backup failed, err: ${err}`);
    return;
  }
  console.info(`Backup success.`);
})

backup

backup(destName:string): Promise<void>

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

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Return value

Example

let promiseBackup = store.backup("dbBackup.db");
promiseBackup.then(()=>{
  console.info(`Backup success.`);
}).catch((err)=>{
  console.error(`Backup failed, err: ${err}`);
})

restore

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

Restores an RDB store from a backup file. This API uses an asynchronous callback to return the result.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Example

store.restore("dbBackup.db", function(err) {
  if (err) {
    console.error(`Restore failed, err: ${err}`);
    return;
  }
  console.info(`Restore success.`);
})

restore

restore(srcName:string): Promise<void>

Restores an RDB store from a backup file. This API uses a promise to return the result.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Return value

Example

let promiseRestore = store.restore("dbBackup.db");
promiseRestore.then(()=>{
  console.info(`Restore success.`);
}).catch((err)=>{
  console.error(`Restore failed, err: ${err}`);
})

setDistributedTables

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

Example

store.setDistributedTables(["EMPLOYEE"], function (err) {
  if (err) {
    console.error(`SetDistributedTables failed, err: ${err}`);
    return;
  }
  console.info(`SetDistributedTables successfully.`);
})

setDistributedTables

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

Return value

Example

let promise = store.setDistributedTables(["EMPLOYEE"]);
promise.then(() => {
  console.info(`SetDistributedTables successfully.`);
}).catch((err) => {
  console.error(`SetDistributedTables failed, err: ${err}`);
})

obtainDistributedTableName

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

Example

import deviceManager from '@ohos.distributedHardware.deviceManager';
let dmInstance = null;
let deviceId = null;

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

store.obtainDistributedTableName(deviceId, "EMPLOYEE", function (err, tableName) {
    if (err) {
        console.error(`ObtainDistributedTableName failed, err: ${err}`);
        return;
    }
    console.info(`ObtainDistributedTableName successfully, tableName= ${tableName}`);
})

obtainDistributedTableName

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

Return value

Example

import deviceManager from '@ohos.distributedHardware.deviceManager';
let dmInstance = null;
let deviceId = null;

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

let promise = store.obtainDistributedTableName(deviceId, "EMPLOYEE");
promise.then((tableName) => {
  console.info(`ObtainDistributedTableName successfully, tableName= ${tableName}`);
}).catch((err) => {
  console.error(`ObtainDistributedTableName failed, err: ${err}`);
})

sync

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

Example

import deviceManager from '@ohos.distributedHardware.deviceManager';
let dmInstance = null;
let deviceIds = [];

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

let predicates = new relationalStore.RdbPredicates('EMPLOYEE');
predicates.inDevices(deviceIds);
store.sync(relationalStore.SyncMode.SYNC_MODE_PUSH, predicates, function (err, result) {
  if (err) {
    console.error(`Sync failed, err: ${err}`);
    return;
  }
  console.info(`Sync done.`);
  for (let i = 0; i < result.length; i++) {
    console.info(`device= ${result[i][0]}, status= ${result[i][1]}`);
  }
})

sync

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

Return value

Example

import deviceManager from '@ohos.distributedHardware.deviceManager';
let dmInstance = null;
let deviceIds = [];

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

let predicates = new relationalStore.RdbPredicates('EMPLOYEE');
predicates.inDevices(deviceIds);
let promise = store.sync(relationalStore.SyncMode.SYNC_MODE_PUSH, predicates);
promise.then((result) =>{
  console.info(`Sync done.`);
  for (let i = 0; i < result.length; i++) {
    console.info(`device= ${result[i][0]}, status= ${result[i][1]}`);
  }
}).catch((err) => {
  console.error(`Sync failed, err: ${err}`);
})

on('dataChange')

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

Example

function storeObserver(devices) {
  for (let i = 0; i < devices.length; i++) {
    console.info(`device= ${devices[i]} data changed`);
  }
}
try {
  store.on('dataChange', relationalStore.SubscribeType.SUBSCRIBE_TYPE_REMOTE, storeObserver);
} catch (err) {
  console.error(`Register observer failed, err: ${err}`);
}

off('dataChange')

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

Example

function storeObserver(devices) {
  for (let i = 0; i < devices.length; i++) {
    console.info(`device= ${devices[i]} data changed`);
  }
}
try {
  store.off('dataChange', relationalStore.SubscribeType.SUBSCRIBE_TYPE_REMOTE, storeObserver);
} catch (err) {
  console.error(`Unregister observer failed, err: ${err}`);
}

ResultSet

Provides APIs to access the result set obtained by querying the RDB store. A result set is a set of results returned after query() is called.

Usage

Obtain the resultSet object first.

let resultSet = null;
let predicates = new relationalStore.RdbPredicates("EMPLOYEE");
predicates.equalTo("AGE", 18);
let promise = store.query(predicates, ["ID", "NAME", "AGE", "SALARY", "CODES"]);
promise.then((result) => {
  resultSet = result;
  console.info(`resultSet columnNames: ${resultSet.columnNames}`);
  console.info(`resultSet columnCount: ${resultSet.columnCount}`);
});

Attributes

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

getColumnIndex

getColumnIndex(columnName: string): number

Obtains the column index based on the column name.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Return value

Error codes

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

Example

resultSet.goToFirstRow();
const id = resultSet.getLong(resultSet.getColumnIndex("ID"));
const name = resultSet.getString(resultSet.getColumnIndex("NAME"));
const age = resultSet.getLong(resultSet.getColumnIndex("AGE"));
const salary = resultSet.getDouble(resultSet.getColumnIndex("SALARY"));

getColumnName

getColumnName(columnIndex: number): string

Obtains the column name based on the specified column index.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Return value

Error codes

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

Example

const id = resultSet.getColumnName(0);
const name = resultSet.getColumnName(1);
const age = resultSet.getColumnName(2);

goTo

goTo(offset:number): boolean

Moves the cursor to the row based on the specified offset.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Return value

Error codes

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

Example

let predicates = new relationalStore.RdbPredicates("EMPLOYEE");
let promise= store.query(predicates, ["ID", "NAME", "AGE", "SALARY", "CODES"]);
promise.then((resultSet) => {
resultSet.goTo(1);
resultSet.close();
}).catch((err) => {
console.error(`query failed, err: ${err}`);
});

goToRow

goToRow(position: number): boolean

Moves to the specified row in the result set.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Return value

Error codes

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

Example

let predicates = new relationalStore.RdbPredicates("EMPLOYEE");
let promise = store.query(predicates, ["ID", "NAME", "AGE", "SALARY", "CODES"]);
promise.then((resultSet) => {
resultSet.goToRow(5);
resultSet.close();
}).catch((err) => {
console.error(`query failed, err: ${err}`);
});

goToFirstRow

goToFirstRow(): boolean

Moves to the first row of the result set.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Return value

Error codes

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

Example

let predicates = new relationalStore.RdbPredicates("EMPLOYEE");
let promise = store.query(predicates, ["ID", "NAME", "AGE", "SALARY", "CODES"]);
promise.then((resultSet) => {
resultSet.goToFirstRow();
resultSet.close();
}).catch((err) => {
console.error(`query failed, err: ${err}`);
});

goToLastRow

goToLastRow(): boolean

Moves to the last row of the result set.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Return value

Error codes

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

Example

let predicates = new relationalStore.RdbPredicates("EMPLOYEE");
let promise = store.query(predicates, ["ID", "NAME", "AGE", "SALARY", "CODES"]);
promise.then((resultSet) => {
resultSet.goToLastRow();
resultSet.close();
}).catch((err) => {
console.error(`query failed, err: ${err}`);
});

goToNextRow

goToNextRow(): boolean

Moves to the next row in the result set.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Return value

Error codes

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

Example

let predicates = new relationalStore.RdbPredicates("EMPLOYEE");
let promise = store.query(predicates, ["ID", "NAME", "AGE", "SALARY", "CODES"]);
promise.then((resultSet) => {
resultSet.goToNextRow();
resultSet.close();
}).catch((err) => {
console.error(`query failed, err: ${err}`);
});

goToPreviousRow

goToPreviousRow(): boolean

Moves to the previous row in the result set.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Return value

Error codes

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

Example

let predicates = new relationalStore.RdbPredicates("EMPLOYEE");
let promise = store.query(predicates, ["ID", "NAME", "AGE", "SALARY", "CODES"]);
promise.then((resultSet) => {
resultSet.goToPreviousRow();
resultSet.close();
}).catch((err) => {
console.error(`query failed, err: ${err}`);
});

getBlob

getBlob(columnIndex: number): Uint8Array

Obtains the value in the form of a byte array based on the specified column and the current row.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Return value

Error codes

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

Example

const codes = resultSet.getBlob(resultSet.getColumnIndex("CODES"));

getString

getString(columnIndex: number): string

Obtains the value in the form of a string based on the specified column and the current row.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Return value

Error codes

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

Example

const name = resultSet.getString(resultSet.getColumnIndex("NAME"));

getLong

getLong(columnIndex: number): number

Obtains the value of the Long type based on the specified column and the current row.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Return value

Error codes

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

Example

const age = resultSet.getLong(resultSet.getColumnIndex("AGE"));

getDouble

getDouble(columnIndex: number): number

Obtains the value of the double type based on the specified column and the current row.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Return value

Error codes

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

Example

const salary = resultSet.getDouble(resultSet.getColumnIndex("SALARY"));

isColumnNull

isColumnNull(columnIndex: number): boolean

Checks whether the value in the specified column is null.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Parameters

Return value

Error codes

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

Example

const isColumnNull = resultSet.isColumnNull(resultSet.getColumnIndex("CODES"));

close

close(): void

Closes this result set.

System capability: SystemCapability.DistributedDataManager.RelationalStore.Core

Example

let predicatesClose = new relationalStore.RdbPredicates("EMPLOYEE");
let promiseClose = store.query(predicatesClose, ["ID", "NAME", "AGE", "SALARY", "CODES"]);
promiseClose.then((resultSet) => {
resultSet.close();
}).catch((err) => {
console.error(`resultset close failed, err: ${err}`);
});

Error codes

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