@@ -7,7 +7,7 @@ A relational database (RDB) store allows you to operate local data with or witho
## Available APIs
For details about RDB APIs, see [Relational Database](../reference/apis/js-apis-data-rdb.md).
Most of the RDB store APIs are asynchronous interfaces, which can use a callback or promise to return the result. This document uses the promise-based APIs as an example. For details about the APIs, see [Relational Database](../reference/apis/js-apis-data-rdb.md).
### Creating or Deleting an RDB Store
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@@ -15,51 +15,48 @@ The table below describes the APIs available for creating and deleting an RDB st
**Table 1** APIs for creating and deleting an RDB store
| API| Description|
| -------- | -------- |
|getRdbStore(context: Context, config: StoreConfig, version: number, callback: AsyncCallback<RdbStore>): void| Obtains an RDB store. This API uses a callback to return the result. You can set parameters for the RDB store based on service requirements, and then call APIs to perform data operations.<br>- **context**: context of the application or function.<br>- **config**: configuration of the RDB store.<br>- **version**: RDB version.<br>- **callback**: callback invoked to return the RDB store obtained.|
|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 then call APIs to perform data operations.<br>- **context**: context of the application or function.<br>- **config**: configuration of the RDB store.<br>- **version**: RDB version.|
|deleteRdbStore(context: Context, name: string, callback: AsyncCallback<void> ): void | Deletes an RDB store. This API uses a callback to return the result. <br>- **context**: context of the application or function.<br>- **name**: RDB store to delete.<br>- **callback**: callback invoked to return the result.|
| deleteRdbStore(context: Context, name: string): Promise<void> | Deletes an RDB store. This API uses a promise to return the result.<br>- **context**: context of the application or function.<br>- **name**: RDB store to delete.|
| 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.<br>- **context**: context of the application or function.<br>- **config**: configuration of the RDB store.<br>- **version**: version of the RDB store.|
| deleteRdbStore(context: Context, name: string): Promise<void> | Deletes an RDB store. This API uses a promise to return the result.<br>- **context**: context of the application or function.<br>- **name**: name of the RDB store to delete.|
### Managing Data in an RDB Store
The RDB provides APIs for inserting, deleting, updating, and querying data in the local RDB store.
-**Inserting data**
-**Inserting Data**
The RDB provides APIs for inserting data through a **ValuesBucket** in a data table. If the data is inserted, the row ID of the data inserted will be returned; otherwise, **-1** will be returned.
**Table 2** APIs for inserting data
**Table 2** API for inserting data
| Class| API| Description|
| -------- | -------- | -------- |
| RdbStore | insert(table: string, values: ValuesBucket, callback: AsyncCallback<number>):void | Inserts a row of data into a table. This API uses a callback to return the result.<br>- **table**: name of the target table.<br>- **values**: data to be inserted into the table.<br>- **callback**: callback invoked to return the result. If the operation is successful, the row ID will be returned; otherwise, **-1** will be returned.|
| RdbStore | insert(table: string, values: ValuesBucket): Promise<number> | Inserts a row of data into a table. This API uses a promise to return the result.<br>- **table**: name of the target table.<br>- **values**: data to be inserted into the table.|
| RdbStore | insert(table:string,values:ValuesBucket):Promise<number> | Inserts a row of data into a table. This API uses a promise to return the result.<br>If the operation is successful, the row ID will be returned; otherwise, **-1** will be returned.<br>- **table**: name of the target table.<br>- **values**: data to be inserted into the table.|
-**Updating data**
-**Updating Data**
Call the **update()** method to pass new data and specify the update conditions by using **RdbPredicates**. If the data is updated, the number of rows of the updated data will be returned; otherwise, **0** will be returned.
**Table 3** APIs for updating data
**Table 3** API for updating data
| Class| API| Description|
| -------- | -------- | -------- |
| RdbStore | update(values: ValuesBucket, predicates: RdbPredicates, callback: AsyncCallback<number>):void | Updates data in the RDB store based on the specified **RdbPredicates** object. This API uses a callback to return the result.<br>- **values**: data to update, which is stored in a **ValuesBucket**.<br>- **predicates**: conditions for updating data.<br>- **callback**: callback invoked to return the number of rows updated.|
| RdbStore | update(values: ValuesBucket, predicates: RdbPredicates): Promise<number> | Updates data in the RDB store based on the specified **RdbPredicates** object. This API uses a promise to return the result.<br>- **values**: data to update, which is stored in a **ValuesBucket**.<br>- **predicates**: conditions for updating data.|
| RdbStore | update(values:ValuesBucket,predicates:RdbPredicates):Promise<number> | Updates data based on the specified **RdbPredicates** object. This API uses a promise to return the result.<br/>- **values**: data to update, which is stored in **ValuesBucket**.<br>- **predicates**: conditions for updating data.<br/>Return value: number of rows updated. |
-**Deleting data**
-**Deleting Data**
Call the **delete()** method to delete data meeting the conditions specified by **RdbPredicates**. If the data is deleted, the number of rows of the deleted data will be returned; otherwise, **0** will be returned.
**Table 4** APIs for deleting data
**Table 4** API for deleting data
| Class| API| Description|
| -------- | -------- | -------- |
| RdbStore | 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.<br>- **predicates**: conditions for deleting data.<br>- **callback**: callback invoked to return the number of rows updated.|
| RdbStore | 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.<br>- **predicates**: conditions for deleting data.|
| RdbStore | 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.<br>- **predicates**: conditions for deleting data.<br/>Return value: number of rows updated. |
-**Querying data**
-**Querying Data**
You can query data in an RDB store in either of the following ways:
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@@ -68,78 +65,48 @@ The RDB provides APIs for inserting, deleting, updating, and querying data in th
**Table 5** APIs for querying data
| Class| API| Description|
| -------- | -------- | -------- |
| RdbStore | query(predicates: RdbPredicates, columns: Array<string>, callback: AsyncCallback<ResultSet>): void | Queries data in the RDB store based on the specified **RdbPredicates** object. This API uses a callback to return the result.<br>- **predicates**: conditions for querying data.<br>- **columns**: columns to query. If this parameter is not specified, the query applies to all columns.<br>- **callback**: callback invoked to return the result. If the operation is successful, a **ResultSet** object will be returned.|
| RdbStore | query(predicates: RdbPredicates, columns?: Array<string>): Promise<ResultSet> | Queries data in the RDB store based on the specified **RdbPredicates** object. This API uses a promise to return the result.<br>- **predicates**: conditions for querying data.<br>- **columns**: columns to query. If this parameter is not specified, the query applies to all columns.|
| RdbStore | querySql(sql: string, bindArgs: Array<ValueType>, callback: AsyncCallback<ResultSet>):void | Queries data in the RDB store using the specified SQL statement. This API uses a callback to return the result.<br>- **sql**: SQL statement.<br>- **bindArgs**: arguments in the SQL statement.<br>- **callback**: callback invoked to return the result. If the operation is successful, a **ResultSet** object will be returned.|
| RdbStore | querySql(sql: string, bindArgs?: Array<ValueType>):Promise<ResultSet> | Queries data in the RDB store using the specified SQL statement. This API uses a promise to return the result.<br>- **sql**: SQL statement.<br>- **bindArgs**: arguments in the SQL statement.|
| RdbStore | 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.<br>- **device**: network ID of the remote device.<br>- **table**: name of the table to query.<br>- **predicates**: conditions for querying data.<br>- **columns**: columns to query. If this parameter is not specified, the query applies to all columns.<br>- **callback**: callback invoked to return the result. If the operation is successful, a **ResultSet** object will be returned.|
| RdbStore | 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.<br>- **device**: network ID of the remote device.<br>- **table**: name of the table to query.<br>- **predicates**: conditions for querying data.<br>- **columns**: columns to query. If this parameter is not specified, the query applies to all columns.|
| RdbStore | 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.<br>- **predicates**: conditions for querying data.<br>- **columns**: columns to query. If this parameter is not specified, the query applies to all columns.|
| RdbStore | querySql(sql:string,bindArgs?:Array<ValueType>):Promise<ResultSet> | Queries data using the specified SQL statement. This API uses a promise to return the result.<br>- **sql**: SQL statement.<br>- **bindArgs**: arguments in the SQL statement.|
| RdbStore | remoteQuery(device: string, table: string, predicates: RdbPredicates, columns: Array<string>): Promise<ResultSet> | Queries data from the database of a remote device based on specified conditions. This API uses a promise to return the result.<br>- **device**: network ID of the remote device.<br>- **table**: name of the table to be queried.<br>- **predicates**: **RdbPredicates** that specifies the query condition.<br>- **columns**: columns to query. If this parameter is not specified, the query applies to all columns.|
### Using Predicates
The RDB provides **RdbPredicates** for you to set database operation conditions.
The following lists common predicates. For more information about predicates, see [**RdbPredicates**](../reference/apis/js-apis-data-rdb.md#rdbpredicates).
**Table 6** APIs for using RDB store predicates
| Class| API| Description|
| -------- | -------- | -------- |
| RdbPredicates |inDevices(devices: Array\<string>): RdbPredicates | Specifies remote devices on the network with RDB stores to be synchronized.<br>- **devices**: IDs of the remote devices on the network.<br>- **RdbPredicates**: returns a **RdbPredicates** object that matches the specified field.|
| RdbPredicates |inAllDevices(): RdbPredicates | Connects to all remote devices on the network with RDB stores to be synchronized.<br>- **RdbPredicates**: returns a **RdbPredicates** object that matches the specified field.|
| RdbPredicates | equalTo(field: string, value: ValueType): RdbPredicates | Sets an **RdbPredicates** to match the field with data type **ValueType** and value equal to the specified value.<br>- **field**: column name in the database table.<br>- **value**: value specified.<br>- **RdbPredicates**: returns a **RdbPredicates** object that matches the specified field.|
| RdbPredicates | 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.<br>- **field**: column name in the database table.<br>- **value**: value specified.<br>- **RdbPredicates**: returns a **RdbPredicates** object that matches the specified field.|
| RdbPredicates | beginWrap(): RdbPredicates | Adds a left parenthesis to the **RdbPredicates**.<br>- **RdbPredicates**: returns a **RdbPredicates** with a left parenthesis.|
| RdbPredicates | endWrap(): RdbPredicates | Adds a right parenthesis to the **RdbPredicates**.<br>- **RdbPredicates**: returns a **RdbPredicates** with a right parenthesis.|
| RdbPredicates | or(): RdbPredicates | Adds the OR condition to the **RdbPredicates**.<br>- **RdbPredicates**: returns a **RdbPredicates** with the OR condition.|
| RdbPredicates | and(): RdbPredicates | Adds the AND condition to the **RdbPredicates**.<br>- **RdbPredicates**: returns a **RdbPredicates** with the AND condition.|
| RdbPredicates | contains(field: string, value: string): RdbPredicates | Sets an **RdbPredicates** to match a string containing the specified value.<br>- **field**: column name in the database table.<br>- **value**: value specified.<br>- **RdbPredicates**: returns a **RdbPredicates** object that matches the specified string.|
| RdbPredicates | beginsWith(field: string, value: string): RdbPredicates | Sets an **RdbPredicates** to match a string that starts with the specified value.<br>- **field**: column name in the database table.<br>- **value**: value specified.<br>- **RdbPredicates**: returns a **RdbPredicates** object that matches the specified field.|
| RdbPredicates | endsWith(field: string, value: string): RdbPredicates | Sets an **RdbPredicates** to match a string that ends with the specified value.<br>- **field**: column name in the database table.<br>- **value**: value specified.<br>- **RdbPredicates**: returns a **RdbPredicates** object that matches the specified field.|
| RdbPredicates | isNull(field: string): RdbPredicates | Sets an **RdbPredicates** to match the field whose value is null.<br>- **field**: column name in the database table.<br>- **RdbPredicates**: returns a **RdbPredicates** object that matches the specified field.|
| RdbPredicates | isNotNull(field: string): RdbPredicates | Sets an **RdbPredicates** to match the field whose value is not null.<br>- **field**: column name in the database table.<br>- **RdbPredicates**: returns a **RdbPredicates** object that matches the specified field.|
| RdbPredicates | like(field: string, value: string): RdbPredicates | Sets an **RdbPredicates** to match a string that is similar to the specified value.<br>- **field**: column name in the database table.<br>- **value**: value specified.<br>- **RdbPredicates**: returns a **RdbPredicates** object that matches the specified field.|
| RdbPredicates | glob(field: string, value: string): RdbPredicates | Sets an **RdbPredicates** to match the specified string.<br>- **field**: column name in the database table.<br>- **value**: value specified.<br>- **RdbPredicates**: returns a **RdbPredicates** object that matches the specified field.|
| RdbPredicates | between(field: string, low: ValueType, high: ValueType): RdbPredicates | Sets ta **RdbPredicates** to match the field with data type **ValueType** and value within the specified range.<br>- **field**: column name in the database table.<br>- **low**: minimum value that matches the **RdbPredicates**.<br>- **high**: maximum value that matches the **RdbPredicates**.<br>- **RdbPredicates**: returns a **RdbPredicates** object that matches the specified field.|
| RdbPredicates | 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.<br>- **field**: column name in the database table.<br>- **low**: minimum value that matches the **RdbPredicates**.<br>- **high**: maximum value that matches the **RdbPredicates**.<br>- **RdbPredicates**: returns a **RdbPredicates** object that matches the specified field.|
| RdbPredicates | greaterThan(field: string, value: ValueType): RdbPredicates | Sets an **RdbPredicates** to match the field with data type **ValueType** and value greater than the specified value.<br>- **field**: column name in the database table.<br>- **value**: value specified.<br>- **RdbPredicates**: returns a **RdbPredicates** object that matches the specified field.|
| RdbPredicates | lessThan(field: string, value: ValueType): RdbPredicates | Sets an **RdbPredicates** to match the field with data type **ValueType** and value less than the specified value.<br>- **field**: column name in the database table.<br>- **value**: value specified.<br>- **RdbPredicates**: returns a **RdbPredicates** object that matches the specified field.|
| RdbPredicates | 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.<br>- **field**: column name in the database table.<br>- **value**: value specified.<br>- **RdbPredicates**: returns a **RdbPredicates** object that matches the specified field.|
| RdbPredicates | 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.<br>- **field**: column name in the database table.<br>- **value**: value specified.<br>- **RdbPredicates**: returns a **RdbPredicates** object that matches the specified field.|
| RdbPredicates | orderByAsc(field: string): RdbPredicates | Sets an **RdbPredicates** to match the column with values sorted in ascending order.<br>- **field**: column name in the database table.<br>- **RdbPredicates**: returns a **RdbPredicates** object that matches the specified field.|
| RdbPredicates | orderByDesc(field: string): RdbPredicates | Sets an **RdbPredicates** to match the column with values sorted in descending order.<br>- **field**: column name in the database table.<br>- **RdbPredicates**: returns a **RdbPredicates** object that matches the specified field.|
| RdbPredicates | distinct(): RdbPredicates | Sets an **RdbPredicates** to filter out duplicate records.<br>- **RdbPredicates**: returns a **RdbPredicates** object that can filter out duplicate records.|
| RdbPredicates | limitAs(value: number): RdbPredicates | Sets an **RdbPredicates** to specify the maximum number of records.<br>- **value**: maximum number of records.<br>- **RdbPredicates**: returns a **RdbPredicates** object that can be used to set the maximum number of records.|
| RdbPredicates | offsetAs(rowOffset: number): RdbPredicates | Sets the **RdbPredicates** to specify the start position of the returned result.<br>- **rowOffset**: start position of the returned result. The value is a positive integer.<br>- **RdbPredicates**: returns a **RdbPredicates** object that specifies the start position of the returned result.|
| RdbPredicates | groupBy(fields: Array<string>): RdbPredicates | Sets an **RdbPredicates** to group rows that have the same value into summary rows.<br>- **fields**: names of the columns grouped for querying data.<br>- **RdbPredicates**: returns a **RdbPredicates** object that groups rows with the same value.|
| RdbPredicates | indexedBy(indexName: string): RdbPredicates | Sets an **RdbPredicates** to specify the index column.<br>- **indexName**: name of the index column.<br>- **RdbPredicates**: returns a **RdbPredicates** object that specifies the index column.|
| RdbPredicates | 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.<br>- **field**: column name in the database table.<br>- **value**: array of **ValueType** to match.<br>- **RdbPredicates**: returns a **RdbPredicates** object that matches the specified field.|
| RdbPredicates | 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.<br>- **field**: column name in the database table.<br>- **value**: array of **ValueType** to match.<br>- **RdbPredicates**: returns a **RdbPredicates** object that matches the specified field.|
| RdbPredicates | equalTo(field:string,value:ValueType):RdbPredicates | Sets an **RdbPredicates** to match the field with data type **ValueType** and value equal to the specified value.<br>- **field**: column name in the database table.<br>- **value**: value to match the **RdbPredicates**.<br>- **RdbPredicates**: **RdbPredicates** object that matches the specified field.|
| RdbPredicates | 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.<br>- **field**: column name in the database table.<br>- **value**: value to match the **RdbPredicates**.<br>- **RdbPredicates**: **RdbPredicates** object that matches the specified field.|
| RdbPredicates | or():RdbPredicates | Adds the OR condition to the **RdbPredicates**.<br>- **RdbPredicates**: **RdbPredicates** with the OR condition.|
| RdbPredicates | and():RdbPredicates | Adds the AND condition to the **RdbPredicates**.<br>- **RdbPredicates**: **RdbPredicates** with the AND condition.|
| RdbPredicates | contains(field:string,value:string):RdbPredicates | Sets an **RdbPredicates** to match a string containing the specified value.<br>- **field**: column name in the database table.<br>- **value**: value to match the **RdbPredicates**.<br>- **RdbPredicates**: **RdbPredicates** object that matches the specified field.|
### Using the Result Set
A result set can be regarded as a row of data in the queried results. It allows you to traverse and access the data you have queried. The following table describes the external APIs of **ResultSet**.
A result set can be regarded as a row of data in the queried results. It allows you to traverse and access the data you have queried.
For details about how to use result set APIs, see [Result Set](../reference/apis/js-apis-data-resultset.md).
> **NOTICE**<br>
> After a result set is used, you must call the **close()** method to close it explicitly.
**Table 7** APIs for using the result set
| Class| API| Description|
| -------- | -------- | -------- |
| ResultSet | goTo(offset:number): boolean | Moves the result set forwards or backwards by the specified offset relative to its current position.|
| ResultSet | goToRow(position: number): boolean | Moves the result set to the specified row.|
| ResultSet | goToNextRow(): boolean | Moves the result set to the next row.|
| ResultSet | goToPreviousRow(): boolean | Moves the result set to the previous row.|
| ResultSet | getColumnIndex(columnName: string): number | Obtains the column index based on the specified column name.|
| ResultSet | getColumnName(columnIndex: number): string | Obtains the column name based on the specified column index.|
| ResultSet | goToFirstRow(): boolean | Moves to the first row of the result set.|
| ResultSet | goToLastRow(): boolean | Moves to the last row of the result set.|
| ResultSet | getString(columnIndex: number): string | Obtains the value in the specified column of the current row, in a string.|
| ResultSet | getBlob(columnIndex: number): Uint8Array | Obtains the values in the specified column of the current row, in a byte array.|
| ResultSet | getDouble(columnIndex: number): number | Obtains the values in the specified column of the current row, in double.|
| ResultSet | isColumnNull(columnIndex: number): boolean | Checks whether the value in the specified column of the current row is null.|
| ResultSet | close(): void | Closes the result set.|
| ResultSet | goToFirstRow():boolean | Moves to the first row of the result set. |
| ResultSet | getString(columnIndex:number):string | Obtains the value in the form of a string based on the specified column and current row. |
| ResultSet | getBlob(columnIndex:number):Uint8Array | Obtains the value in the form of a byte array based on the specified column and the current row.|
| ResultSet | getDouble(columnIndex:number):number | Obtains the value in the form of double based on the specified column and current row. |
| ResultSet | getLong(columnIndex:number):number | Obtains the value in the form of a long integer based on the specified column and current row. |
| ResultSet | close():void | Closes the result set. |
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**Setting Distributed Tables**
**Table 8** APIs for setting distributed tables
**Table 8** API for setting distributed tables
| Class| API| Description|
| -------- | -------- | -------- |
| RdbStore | setDistributedTables(tables: Array\<string>, callback: AsyncCallback\<void>): void | Sets a list of distributed tables. This API uses a callback to return the result.<br>- **tables**: names of the distributed tables to set.<br>- **callback**: callback invoked to return the result.|
| RdbStore | setDistributedTables(tables: Array\<string>): Promise\<void> | Sets a list of distributed tables. This API uses a promise to return the result.<br>- **tables**: names of the distributed tables to set.|
| RdbStore | setDistributedTables(tables: Array\<string>): Promise\<void> | Sets distributed tables. This API uses a promise to return the result.<br>- **tables**: names of the distributed tables to set.|
**Obtaining the Distributed Table Name for a Remote Device**
You can obtain the distributed table name for a remote device based on the local table name. The distributed table name can be used to query the RDB store of the remote device.
**Table 9** APIs for obtaining the distributed table name of a remote device
**Table 9** API for obtaining the distributed table name of a remote device
| Class| API| Description|
| -------- | -------- | -------- |
| RdbStore | obtainDistributedTableName(device: string, table: string, callback: AsyncCallback\<string>): void | Obtains the distributed table name for a remote device based on the local table name. The distributed table name is required when the database of a remote device is queried. This API uses an asynchronous callback to return the result.<br>- **device**: remote device.<br>- **table**: local table name.<br>- **callback**: callback used to return the result. If the operation is successful, the distributed table name of the remote device will be returned.|
| RdbStore | obtainDistributedTableName(device: string, table: string): Promise\<string> | Obtains the distributed table name for a remote device based on the local table name. The distributed table name is used to query the RDB store of the remote device. This API uses a promise to return the result.<br>- **device**: remote device.<br>- **table**: local table name.|
| RdbStore | obtainDistributedTableName(device: string, table: string): Promise\<string> | Obtains the distributed table name for a remote device based on the local table name. The distributed table name is required when the RDB store of a remote device is queried. This API uses a promise to return the result.<br>- **device**: remote device.<br>- **table**: local table name.|
**Synchronizing Data Between Devices**
**Table 10** APIs for synchronizing data between devices
**Table 10** API for synchronizing data between devices
| Class| API| Description|
| -------- | -------- | -------- |
| RdbStore | sync(mode: SyncMode, predicates: RdbPredicates, callback: AsyncCallback\<Array\<[string, number]>>): void | Synchronizes data between devices. This API uses a callback to return the result.<br>- **mode**: data synchronization mode. **SYNC_MODE_PUSH** means to push data from the local device to a remote device. **SYNC_MODE_PULL** means to pull data from a remote device to the local device.<br>- **predicates**: data and devices to be synchronized.<br>- **callback**: callback invoked to return the result. In the result, **string** indicates the device ID, and **number** indicates the synchronization status of each device. The value **0** indicates a success, and other values indicate a failure.|
| RdbStore | sync(mode: SyncMode, predicates: RdbPredicates): Promise\<Array\<[string, number]>> | Synchronizes data between devices. This API uses a promise to return the result.<br>- **mode**: data synchronization mode. **SYNC_MODE_PUSH** means to push data from the local device to a remote device. **SYNC_MODE_PULL** means to pull data from a remote device to the local device.<br>- **predicates**: data and devices to be synchronized.|
| RdbStore | sync(mode: SyncMode, predicates: RdbPredicates): Promise\<Array\<[string, number]>> | Synchronizes data between devices. This API uses a promise to return the result.<br>- **mode**: synchronization mode. **SYNC_MODE_PUSH** means to push data from the local device to a remote device. **SYNC_MODE_PULL** means to pull data from a remote device to the local device.<br>- **predicates**: specifies the data and devices to synchronize.<br>- **string**: device ID. <br>- **number**: synchronization status of that device. The value **0** indicates a successful synchronization. Other values indicate a synchronization failure.|
**Registering an RDB Store Observer**
**Table 11** API for registering an observer
| Class| API| Description|
| -------- | -------- | -------- |
| RdbStore |on(event: 'dataChange', type: SubscribeType, observer: Callback\<Array\<string>>): void| Registers an observer for this RDB store to subscribe to distributed data changes. When data in the RDB store changes, a callback will be invoked to return the data changes.<br>- **type**: subscription type. **SUBSCRIBE_TYPE_REMOTE** means to subscribe to remote data changes.<br>- **observer**: observer that listens for data changes in the RDB store.|
| RdbStore | on(event: 'dataChange', type: SubscribeType, observer: Callback\<Array\<string>>): void | Registers an observer for this RDB store to subscribe to distributed data changes. When data in the RDB store changes, a callback will be invoked to return the data changes.<br>- **type**: subscription type. **SUBSCRIBE_TYPE_REMOTE** means to subscribe to remote data changes.<br>- **observer**: observer that listens for data changes in the RDB store.|
**Unregistering an RDB Store Observer**
**Table 12** API for unregistering an observer
| Class| API| Description|
| -------- | -------- | -------- |
| RdbStore |off(event:'dataChange', type: SubscribeType, observer: Callback\<Array\<string>>): void;| Unregisters the observer of the specified type for the RDB store. This API uses a callback to return the result.<br>- **type**: subscription type. **SUBSCRIBE_TYPE_REMOTE** means to subscribe to remote data changes.<br>- **observer**: observer to unregister.|
| RdbStore | off(event:'dataChange', type: SubscribeType, observer: Callback\<Array\<string>>): void; | Unregisters the observer of the specified type from the RDB store. This API uses an asynchronous callback to return the result.<br>- **type**: subscription type. **SUBSCRIBE_TYPE_REMOTE** means to subscribe to remote data changes.<br>- **observer**: observer to unregister.|
### Backing Up and Restoring an RDB Store
**Backing Up an RDB Store**
**Table 13** APIs for backing up an RDB store
**Table 13** API for backing up an RDB store
| Class| API| Description|
| -------- | -------- | -------- |
| RdbStore |backup(destName:string, callback: AsyncCallback<void>):void| Backs up an RDB store. This API uses an asynchronous callback to return the result.<br>- **destName**: name of the RDB backup file.<br>- **callback**: callback invoked to return the result.|
| RdbStore |backup(destName:string): Promise<void>| Backs up an RDB store. This API uses a promise to return the result.<br>- **destName**: name of the RDB backup file.|
| RdbStore | backup(destName:string): Promise<void> | Backs up an RDB store. This API uses a promise to return the result.<br>- **destName**: name of the RDB backup file.|
**Restoring an RDB Store**
**Table 14** APIs for restoring an RDB store
**Table 14** API for restoring an RDB store
| Class| API| Description|
| -------- | -------- | -------- |
| RdbStore |restore(srcName:string, callback: AsyncCallback<void>):void| Restores an RDB store using a backup file. This API uses an asynchronous callback to return the result.<br>- **srcName**: name of the RDB backup file.<br>- **callback**: callback invoked to return the result.|
| RdbStore |restore(srcName:string): Promise<void>| Restores an RDB store using a backup file. This API uses a promise to return the result.<br>- **srcName**: name of the RDB backup file.|
| RdbStore | restore(srcName:string): Promise<void> | Restores an RDB store from a backup file. This API uses a promise to return the result.<br>- **srcName**: name of the backup file used to restore the RDB store.|
**Transaction**
Table 15 Transaction APIs
| Class| API| Description|
| -------- | -------- | -------- |
| RdbStore |beginTransaction():void| Starts the transaction before executing SQL statements.|
| RdbStore |commit():void| Commits the executed SQL statements.|
| RdbStore |rollBack():void| Rolls back the SQL statements that have been executed.|
@@ -4,7 +4,7 @@ The relational database (RDB) manages data based on relational models. With the
This module provides the following RDB-related functions:
-[RdbPredicates](#rdbpredicates): 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.
-[RdbPredicates](#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](#rdbstore): provides APIs for managing an RDB store.
> **NOTE**<br/>
...
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@@ -166,14 +166,14 @@ let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
Before using the following APIs, use [executeSql](#executesql) to initialize the database table structure and related data. For details, see [RDB Development](../../database/database-relational-guidelines.md).
### insert
...
...
@@ -977,7 +979,7 @@ rdbStore.insert("EMPLOYEE", valueBucket, function (status, rowId) {
console.log("Failed to insert data");
return;
}
console.log("Inserted data, rowId = "+rowId);
console.log("Inserted data successfully, rowId = "+rowId);
| values | [ValuesBucket](#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.|
| values | [ValuesBucket](#valuesbucket) | Yes| Data to update. The key-value pair is associated with the column name in the target table.|
| predicates | [RdbPredicates](#rdbpredicates) | Yes| Update conditions specified by the **RdbPredicates** object.|
| callback | AsyncCallback<number> | Yes| Callback invoked to return the number of rows updated.|
...
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@@ -1158,7 +1160,7 @@ Updates data based on the specified **RdbPredicates** object. This API uses a pr
**Parameters**
| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| values | [ValuesBucket](#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.|
| values | [ValuesBucket](#valuesbucket) | Yes| Data to update. The key-value pair is associated with the column name in the target table.|
| predicates | [RdbPredicates](#rdbpredicates) | Yes| Update conditions specified by the **RdbPredicates** object.|
@@ -1520,7 +1522,7 @@ Queries data from the RDB store of a remote device based on specified conditions
| -------- | -------- | -------- | -------- |
| device | string | Yes| Network ID of the remote device.|
| table | string | Yes| Name of the target table.|
| predicates | [RdbPredicates](#rdbpredicates) | Yes| Conditions for querying data.|
| predicates | [RdbPredicates](#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](js-apis-data-resultset.md#resultset)> | Yes| Callback invoked to return the result. If the operation is successful, a **ResultSet** object will be returned.|
...
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@@ -1553,7 +1555,7 @@ Queries data from the RDB store of a remote device based on specified conditions
| -------- | -------- | -------- | -------- |
| device | string | Yes| Network ID of the remote device.|
| table | string | Yes| Name of the target table.|
| predicates | [RdbPredicates](#rdbpredicates) | Yes| Conditions for querying data.|
| predicates | [RdbPredicates](#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.|
@@ -1588,7 +1590,7 @@ Queries data using the specified SQL statement. This API uses an asynchronous ca
| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| sql | string | Yes| SQL statement to run.|
| bindArgs | Array<[ValueType](#valuetype)> | Yes| Values of the parameters in the SQL statement.|
| bindArgs | Array<[ValueType](#valuetype)> | Yes| Arguments in the SQL statement.|
| callback | AsyncCallback<[ResultSet](js-apis-data-resultset.md)> | Yes| Callback invoked to return the result. If the operation is successful, a **ResultSet** object will be returned.|
**Example**
...
...
@@ -1608,7 +1610,7 @@ rdbStore.querySql("SELECT * FROM EMPLOYEE CROSS JOIN BOOK WHERE BOOK.NAME = ?",
@@ -1680,14 +1682,14 @@ Executes an SQL statement that contains specified arguments but returns no value
**Return value**
| Type| Description|
| -------- | -------- |
| Promise<void> | Promise that returns no value.|
| Promise<void> | Promise used to return the result.|
**Example**
```js
constSQL_CREATE_TABLE="CREATE TABLE IF NOT EXISTS EMPLOYEE (ID INTEGER PRIMARY KEY AUTOINCREMENT, NAME TEXT NOT NULL, AGE INTEGER, SALARY REAL, CODES BLOB)"
Obtains the distributed table name for a remote device based on the local table name. The distributed table name is required when the RDB store of a remote device is queried. This API uses an asynchronous callback to return the result.
Obtains the distributed table name for a remote device based on the local table name. This API uses an asynchronous callback to return the result. The distributed table name is required when the RDB store of a remote device is queried.
Obtains the distributed table name for a remote device based on the local table name. The distributed table name is required when the RDB store of a remote device is queried. This API uses a promise to return the result.
Obtains the distributed table name for a remote device based on the local table name. This API uses a promise to return the result. The distributed table name is required when the RDB store of a remote device is queried.
@@ -2003,7 +2005,7 @@ Synchronizes data between devices. This API uses an asynchronous callback to ret
| -------- | -------- | -------- | -------- |
| mode | [SyncMode](#syncmode8) | Yes| Data synchronization mode. The value can be **push** or **pull**.|
| predicates | [RdbPredicates](#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. <br>**string** indicates the device ID. <br>**number** indicates the synchronization status of each device. The value **0** indicates a successful synchronization. Other values indicate a synchronization failure. |
| callback | AsyncCallback<Array<[string, number]>> | Yes| Callback invoked to send the synchronization result to the caller. <br>**string** indicates the device ID. <br>**number** indicates the synchronization status of that device. The value **0** indicates a successful synchronization. Other values indicate a synchronization failure. |
**Example**
```js
...
...
@@ -2042,7 +2044,7 @@ Synchronizes data between devices. This API uses a promise to return the result.
| Type| Description|
| -------- | -------- |
| Promise<Array<[string, number]>> | Promise used to return the synchronization result to the caller. <br>**string** indicates the device ID. <br>**number** indicates the synchronization status of each device. The value **0** indicates a successful synchronization. Other values indicate a synchronization failure. |
| Promise<Array<[string, number]>> | Promise used to return the synchronization result to the caller. <br>**string** indicates the device ID. <br>**number** indicates the synchronization status of that device. The value **0** indicates a successful synchronization. Other values indicate a synchronization failure. |
