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en/application-dev/database/database-relational-guidelines.md
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...@@ -6,57 +6,52 @@ A relational database (RDB) store allows you to operate local data with or witho ...@@ -6,57 +6,52 @@ A relational database (RDB) store allows you to operate local data with or witho
## Available APIs ## 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 ### Creating or Deleting an RDB Store
The following table describes the APIs available for creating and deleting an RDB store. The table below describes the APIs available for creating and deleting an RDB store.
**Table 1** APIs for creating and deleting an RDB store **Table 1** APIs for creating and deleting an RDB store
| API| Description| | API| Description|
| -------- | -------- | | -------- | -------- |
|getRdbStore(config: StoreConfig, version: number, callback: AsyncCallback&lt;RdbStore&gt;): 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>- **config**: configuration of the RDB store.<br>- **version**: RDB version.<br>- **callback**: callback invoked to return the RDB store obtained.| |getRdbStore(config:StoreConfig,version:number):Promise&lt;RdbStore&gt; | 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>- **config**: configuration of the RDB store.<br>- **version**: version of the RDB store.|
|getRdbStore(config: StoreConfig, version: number): Promise&lt;RdbStore&gt; | 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>- **config**: configuration of the RDB store.<br>- **version**: RDB version.| | deleteRdbStore(name:string):Promise&lt;void&gt; | Deletes an RDB store. This API uses a promise to return the result.<br>- **name**: name of the RDB store to delete.|
|deleteRdbStore(name: string, callback: AsyncCallback&lt;void&gt;): void | Deletes an RDB store. This API uses a callback to return the result. <br>- **name**: RDB store to delete.<br>- **callback**: callback invoked to return the result.|
| deleteRdbStore(name: string): Promise&lt;void&gt; | Deletes an RDB store. This API uses a promise to return the result.<br>- **name**: RDB store to delete.|
### Managing Data in an RDB Store ### Managing Data in an RDB Store
The RDB provides APIs for inserting, deleting, updating, and querying data in the local 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. 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| | Class| API| Description|
| -------- | -------- | -------- | | -------- | -------- | -------- |
| RdbStore | insert(name: string, values: ValuesBucket, callback: AsyncCallback&lt;number&gt;):void | Inserts a row of data into a table. This API uses a callback to return the result.<br>- **name**: 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(name:string,values:ValuesBucket):Promise&lt;number&gt; | 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>- **name**: name of the target table.<br>- **values**: data to be inserted into the table.|
| RdbStore | insert(name: string, values: ValuesBucket): Promise&lt;number&gt; | Inserts a row of data into a table. This API uses a promise to return the result.<br>- **name**: 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. 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| | Class| API| Description|
| -------- | -------- | -------- | | -------- | -------- | -------- |
| RdbStore | update(values: ValuesBucket, rdbPredicates: RdbPredicates, callback: AsyncCallback&lt;number&gt;):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>- **rdbPredicates**: conditions for updating data.<br>- **callback**: callback invoked to return the number of rows updated.| | RdbStore | update(values:ValuesBucket,rdbPredicates:RdbPredicates):Promise\<number> | Updates data based on the specified **RdbPredicates** object. This API uses a promise to return the result.<br>Return value: number of rows updated.<br>- **values**: data to update, which is stored in **ValuesBucket**.<br>- **rdbPredicates**: conditions for updating data. |
| RdbStore | update(values: ValuesBucket, rdbPredicates: 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>- **rdbPredicates**: conditions for updating data.|
- **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. 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| | Class| API| Description|
| -------- | -------- | -------- | | -------- | -------- | -------- |
| RdbStore | delete(rdbPredicates: RdbPredicates, callback: AsyncCallback&lt;number&gt;):void | Deletes data from the database based on the specified **RdbPredicates** object. This API uses a callback to return the result.<br>- **rdbPredicates**: conditions for deleting data.<br>- **callback**: callback invoked to return the number of rows updated.| | RdbStore | delete(rdbPredicates: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>Return value: number of rows updated.<br>- **rdbPredicates**: conditions for deleting data. |
| RdbStore | delete(rdbPredicates: 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>- **rdbPredicates**: conditions for deleting data.|
- **Querying data** - **Querying data**
...@@ -69,74 +64,45 @@ The RDB provides APIs for inserting, deleting, updating, and querying data in th ...@@ -69,74 +64,45 @@ The RDB provides APIs for inserting, deleting, updating, and querying data in th
| Class| API| Description| | Class| API| Description|
| -------- | -------- | -------- | | -------- | -------- | -------- |
| RdbStore | query(rdbPredicates: RdbPredicates, columns: Array, callback: AsyncCallback&lt;ResultSet&gt;): void | Queries data in the RDB store based on the specified **RdbPredicates** object. This API uses a callback to return the result.<br>- **rdbPredicates**: 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(rdbPredicates:RdbPredicates,columns:Array):Promise&lt;ResultSet&gt; | Queries data from the RDB store based on specified conditions. This API uses a promise to return the result.<br>- **rdbPredicates**: conditions for querying data.<br>- **columns**: columns to query. If this parameter is not specified, the query applies to all columns.|
| RdbStore | query(rdbPredicates: RdbPredicates, columns: Array): Promise&lt;ResultSet&gt; | Queries data in the RDB store based on the specified **RdbPredicates** object. This API uses a promise to return the result.<br>- **rdbPredicates**: 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&lt;ValueType&gt;):Promise&lt;ResultSet&gt; | 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 | querySql(sql: string, bindArgs: Array&lt;ValueType&gt;, callback: AsyncCallback&lt;ResultSet&gt;):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&lt;ValueType&gt;):Promise&lt;ResultSet&gt; | 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.|
### Using Predicates ### Using Predicates
The RDB provides **RdbPredicates** for you to set database operation conditions. 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 **Table 6** APIs for using RDB store predicates
| Class| API| Description| | 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 | 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 |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 | 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 | equalTo(field: string, value: ValueType): RdbPredicates | Sets the **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 | or():RdbPredicates | Adds the OR condition to the **RdbPredicates**.<br>- **RdbPredicates**: **RdbPredicates** with the OR condition.|
| RdbPredicates | notEqualTo(field: string, value: ValueType): RdbPredicates | Sets the **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 | and():RdbPredicates | Adds the AND condition to the **RdbPredicates**.<br>- **RdbPredicates**: **RdbPredicates** with the AND condition.|
| RdbPredicates | beginWrap(): RdbPredicates | Adds a left parenthesis to the **RdbPredicates**.<br>- **RdbPredicates**: returns a **RdbPredicates** with a left parenthesis.| | RdbPredicates | contains(field:string,value:string):RdbPredicats | Sets an **RdbPredicates** to match a string that contains 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 | 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): RdbPredicats | Sets the **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 the **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 the **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 the **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 the **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 the **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 the **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 the **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 the **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): RdbPredicatesgr | Sets the **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 the **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 the **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 the **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 the **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 the **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 the **RdbPredicates** to filter out duplicate records.<br>- **RdbPredicates**: returns a **RdbPredicates** object that can filter out duplicate records.|
| RdbPredicates | limitAs(value: number): RdbPredicates | Sets the **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&lt;string&gt;): RdbPredicates | Sets the **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 the **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&lt;ValueType&gt;): RdbPredicates | Sets the **RdbPredicates** to match the field with data type **Array&#60;ValueType&#62;** 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&lt;ValueType&gt;): RdbPredicates | Sets the **RdbPredicates** to match the field with data type **Array&#60;ValueType&#62;** 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.|
### Using the Result Set ### 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.
> ![icon-notice.gif](public_sys-resources/icon-notice.gif) **NOTICE**<br> 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. > After a result set is used, you must call the **close()** method to close it explicitly.
**Table 7** APIs for using the result set **Table 7** APIs for using the result set
| Class| API| Description| | 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 | goToFirstRow():boolean | Moves to the first row of the result set.|
| ResultSet | goToRow(position: number): boolean | Moves the result set to the specified row.| | ResultSet | getString(columnIndex:number):string | Obtains the value in the form of a string based on the specified column and current row.|
| ResultSet | goToNextRow(): boolean | Moves the result set to the next 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 | goToPreviousRow(): boolean | Moves the result set to the previous row.| | ResultSet | getDouble(columnIndex:number):number | Obtains the value in the form of double based on the specified column and current row.|
| ResultSet | getColumnIndex(columnName: string): number | Obtains the column index based on the specified column name.| | ResultSet | getLong(columnIndex:number):number | Obtains the value in the form of a long integer based on the specified column and current row. |
| ResultSet | getColumnName(columnIndex: number): string | Obtains the column name based on the specified column index.| | ResultSet | close():void | Closes the result set.|
| 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.|
...@@ -144,32 +110,29 @@ A result set can be regarded as a row of data in the queried results. It allows ...@@ -144,32 +110,29 @@ A result set can be regarded as a row of data in the queried results. It allows
**Setting Distributed Tables** **Setting Distributed Tables**
**Table 8** APIs for setting distributed tables **Table 8** API for setting distributed tables
| Class| API| Description| | 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 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 a list of 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** **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. 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| | 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 required when the RDB store of a remote device is queried.<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 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.|
**Synchronizing Data Between Devices** **Synchronizing Data Between Devices**
**Table 10** APIs for synchronizing data between devices **Table 10** API for synchronizing data between devices
| Class| API| Description| | 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**: 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. |
| 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. |
**Registering an RDB Store Observer** **Registering an RDB Store Observer**
...@@ -201,7 +164,7 @@ You can obtain the distributed table name for a remote device based on the local ...@@ -201,7 +164,7 @@ You can obtain the distributed table name for a remote device based on the local
import data_rdb from '@ohos.data.rdb' import data_rdb from '@ohos.data.rdb'
const CREATE_TABLE_TEST = "CREATE TABLE IF NOT EXISTS test (" + "id INTEGER PRIMARY KEY AUTOINCREMENT, " + "name TEXT NOT NULL, " + "age INTEGER, " + "salary REAL, " + "blobType BLOB)"; const CREATE_TABLE_TEST = "CREATE TABLE IF NOT EXISTS test (" + "id INTEGER PRIMARY KEY AUTOINCREMENT, " + "name TEXT NOT NULL, " + "age INTEGER, " + "salary REAL, " + "blobType BLOB)";
const STORE_CONFIG = {name: "rdbstore.db",} const STORE_CONFIG = {name: "rdbstore.db"}
data_rdb.getRdbStore(STORE_CONFIG, 1, function (err, rdbStore) { data_rdb.getRdbStore(STORE_CONFIG, 1, function (err, rdbStore) {
rdbStore.executeSql(CREATE_TABLE_TEST ) rdbStore.executeSql(CREATE_TABLE_TEST )
console.info('create table done.') console.info('create table done.')
...@@ -216,7 +179,7 @@ You can obtain the distributed table name for a remote device based on the local ...@@ -216,7 +179,7 @@ You can obtain the distributed table name for a remote device based on the local
```js ```js
var u8 = new Uint8Array([1, 2, 3]) var u8 = new Uint8Array([1, 2, 3])
const valueBucket = {"name": "Tom", "age": 18, "salary": 100.5, "blobType": u8,} const valueBucket = {"name": "Tom", "age": 18, "salary": 100.5, "blobType": u8}
let insertPromise = rdbStore.insert("test", valueBucket) let insertPromise = rdbStore.insert("test", valueBucket)
``` ```
...@@ -253,7 +216,7 @@ You can obtain the distributed table name for a remote device based on the local ...@@ -253,7 +216,7 @@ You can obtain the distributed table name for a remote device based on the local
promise.then(() => { promise.then(() => {
console.info("setDistributedTables success.") console.info("setDistributedTables success.")
}).catch((err) => { }).catch((err) => {
console.info("setDistributedTables failed.") console.info("Failed to set distributed tables.")
}) })
``` ```
...@@ -293,7 +256,7 @@ You can obtain the distributed table name for a remote device based on the local ...@@ -293,7 +256,7 @@ You can obtain the distributed table name for a remote device based on the local
try { try {
rdbStore.on('dataChange', rdb.SubscribeType.SUBSCRIBE_TYPE_REMOTE, storeObserver) rdbStore.on('dataChange', rdb.SubscribeType.SUBSCRIBE_TYPE_REMOTE, storeObserver)
} catch (err) { } catch (err) {
console.log('register observer failed') console.log('Failed to register observer')
} }
``` ```
...@@ -307,4 +270,3 @@ You can obtain the distributed table name for a remote device based on the local ...@@ -307,4 +270,3 @@ You can obtain the distributed table name for a remote device based on the local
let tableName = rdbStore.obtainDistributedTableName(deviceId, "test"); let tableName = rdbStore.obtainDistributedTableName(deviceId, "test");
let resultSet = rdbStore.querySql("SELECT * FROM " + tableName) let resultSet = rdbStore.querySql("SELECT * FROM " + tableName)
``` ```
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