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en/application-dev/database/database-relational-guidelines.md
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......@@ -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
......@@ -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&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>- **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&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>- **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&lt;void&gt; ): 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&lt;void&gt; | 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.|
| API | Description |
| ------------------------------------------------------------ | ------------------------------------------------------------ |
| getRdbStore(context: Context, 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>- **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&lt;void&gt; | 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&lt;number&gt;):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&lt;number&gt; | 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.|
| Class | API | Description |
| -------- | ------------------------------------------------------------ | ------------------------------------------------------------ |
| RdbStore | insert(table: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>- **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&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>- **predicates**: conditions for updating data.<br>- **callback**: callback invoked to return the number of rows updated.|
| RdbStore | update(values: ValuesBucket, predicates: RdbPredicates): Promise&lt;number&gt; | 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.|
| Class | API | Description |
| -------- | ------------------------------------------------------------ | ------------------------------------------------------------ |
| RdbStore | update(values:ValuesBucket,predicates:RdbPredicates):Promise&lt;number&gt; | 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&lt;number&gt;):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&lt;number&gt; | 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.|
| Class | API | Description |
| -------- | ------------------------------------------------------ | ------------------------------------------------------------ |
| RdbStore | delete(predicates:RdbPredicates):Promise&lt;number&gt; | 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:
......@@ -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&lt;string&gt;, 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>- **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&lt;string&gt;): 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>- **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&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.|
| RdbStore | remoteQuery(device: string, table: string, predicates: RdbPredicates, columns: Array&lt;string&gt;, callback: AsyncCallback&lt;ResultSet&gt;): 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&lt;string&gt;): Promise&lt;ResultSet&gt; | 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.|
| Class | API | Description |
| -------- | ------------------------------------------------------------ | ------------------------------------------------------------ |
| RdbStore | query(predicates:RdbPredicates,columns?:Array&lt;string&gt;):Promise&lt;ResultSet&gt; | 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&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 | remoteQuery(device: string, table: string, predicates: RdbPredicates, columns: Array&lt;string&gt;): Promise&lt;ResultSet&gt; | 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&lt;string&gt;): 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&lt;ValueType&gt;): RdbPredicates | Sets an **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 an **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.|
| Class | API | Description |
| ------------- | ------------------------------------------------------------ | ------------------------------------------------------------ |
| 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.|
| Class | API | Description |
| --------- | ---------------------------------------------------- | ------------------------------------------ |
| 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. |
......@@ -149,78 +116,73 @@ A result set can be regarded as a row of data in the queried results. It allows
**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.|
| Class | API | Description |
| -------- | ------------------------------------------------------------ | ------------------------------------------------------------ |
| 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.|
| Class | API | Description |
| -------- | ------------------------------------------------------------ | ------------------------------------------------------------ |
| 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.|
| Class | API | Description |
| -------- | ------------------------------------------------------------ | ------------------------------------------------------------ |
| 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.|
| 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.|
**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.|
| Class | API | Description |
| -------- | ------------------------------------------------------------ | ------------------------------------------------------------ |
| 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&lt;void&gt;):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&lt;void&gt;| Backs up an RDB store. This API uses a promise to return the result.<br>- **destName**: name of the RDB backup file.|
| Class | API | Description |
| -------- | ------------------------------------------------------------ | ------------------------------------------------------------ |
| RdbStore | backup(destName:string): Promise&lt;void&gt; | 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&lt;void&gt;):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&lt;void&gt;| 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.|
| Class | API | Description |
| -------- | ------------------------------------------------------------ | ------------------------------------------------------------ |
| RdbStore | restore(srcName:string): Promise&lt;void&gt; | 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.|
| 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. |
## How to Develop
......@@ -238,7 +200,7 @@ Table 15 Transaction APIs
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 STORE_CONFIG = {name: "rdbstore.db",}
const STORE_CONFIG = {name: "rdbstore.db"}
data_rdb.getRdbStore(this.context, STORE_CONFIG, 1, function (err, rdbStore) {
rdbStore.executeSql(CREATE_TABLE_TEST)
console.info('create table done.')
......@@ -255,7 +217,7 @@ Table 15 Transaction APIs
```js
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)
```
......@@ -424,3 +386,4 @@ Table 15 Transaction APIs
console.info('Restore failed, err: ' + err)
})
```
en/application-dev/reference/apis/js-apis-data-rdb.md
浏览文件 @ 00415c9b
......@@ -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/>
......@@ -166,14 +166,14 @@ let predicates = new data_rdb.RdbPredicates("EMPLOYEE")
inDevices(devices: Array&lt;string&gt;): RdbPredicates
Specifies a remote device on the network during distributed database synchronization.
Connects to the specified remote devices on the network during distributed database synchronization.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| devices | Array&lt;string&gt; | Yes| ID of the remote device to specify.|
| devices | Array&lt;string&gt; | Yes| IDs of the remote devices in the same network.|
**Return value**
| Type| Description|
......@@ -948,6 +948,8 @@ predicates.notIn("NAME", ["Lisa", "Rose"])
Provides methods to manage an RDB store.
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);
})
```
......@@ -1011,7 +1013,7 @@ const valueBucket = {
}
let promise = rdbStore.insert("EMPLOYEE", valueBucket)
promise.then((rowId) => {
console.log("Inserted data, rowId = " + rowId);
console.log("Inserted data successfully, rowId = " + rowId);
}).catch((status) => {
console.log("Failed to insert data");
})
......@@ -1056,10 +1058,10 @@ const valueBucket3 = {
var valueBuckets = new Array(valueBucket1, valueBucket2, valueBucket3);
rdbStore.batchInsert("EMPLOYEE", valueBuckets, function(status, insertNum) {
if (status) {
console.log("bathInsert failed, status = " + status);
console.log("Failed to batch insert data, status = " + status);
return;
}
console.log("bathInsert is successful, the number of values that were inserted = " + insertNum);
console.log("Batch inserted data successfully. The number of values that were inserted = " + insertNum);
})
```
......@@ -1106,9 +1108,9 @@ const valueBucket3 = {
var valueBuckets = new Array(valueBucket1, valueBucket2, valueBucket3);
let promise = rdbStore.batchInsert("EMPLOYEE", valueBuckets);
promise.then((insertNum) => {
console.log("bathInsert is successful, the number of values that were inserted = " + insertNum);
console.log("Batch inserted data successfully. The number of values that were inserted = " + insertNum);
}).catch((status) => {
console.log("bathInsert failed, status = " + status);
console.log("Failed to batch insert data, status = " + status);
})
```
......@@ -1116,14 +1118,14 @@ promise.then((insertNum) => {
update(values: ValuesBucket, predicates: RdbPredicates, callback: AsyncCallback&lt;number&gt;):void
Updates data based on the specified **RdbPredicates** object. This API uses an asynchronous callback to return the result.
Updates data in the RDB store based on the specified **RdbPredicates** object. This API uses an asynchronous callback to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| values | [ValuesBucket](#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&lt;number&gt; | Yes| Callback invoked to return the number of rows updated.|
......@@ -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.|
**Return value**
......@@ -1187,7 +1189,7 @@ promise.then(async (ret) => {
### update<sup>9+</sup>
update(table: string, values: ValuesBucket, predicates: dataSharePredicates.DataSharePredicates, callback: AsyncCallback&lt;number&gt;):void
Updates data based on the specified **DataSharePredicates** object. This API uses an asynchronous callback to return the result.
Updates data in 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
......@@ -1222,7 +1224,7 @@ rdbStore.update("EMPLOYEE", valueBucket, predicates, function (err, ret) {
update(table: string, values: ValuesBucket, predicates: dataSharePredicates.DataSharePredicates):Promise&lt;number&gt;
Updates data based on the specified **DataSharePredicates** object. This API uses a promise to return the result.
Updates data in the RDB store based on the specified **DataSharePredicates** object. This API uses a promise to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -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&lt;string&gt; | Yes| Columns to query. If this parameter is not specified, the query applies to all columns.|
| callback | AsyncCallback&lt;[ResultSet](js-apis-data-resultset.md#resultset)&gt; | Yes| Callback invoked to return the result. If the operation is successful, a **ResultSet** object will be returned.|
......@@ -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&lt;string&gt; | No| Columns to query. If this parameter is not specified, the query applies to all columns.|
**Return value**
......@@ -1580,7 +1582,7 @@ promise.then((resultSet) => {
querySql(sql: string, bindArgs: Array&lt;ValueType&gt;, callback: AsyncCallback&lt;ResultSet&gt;):void
Queries data using the specified SQL statement. This API uses an asynchronous callback to return the result.
Queries data in the RDB store using the specified SQL statement. This API uses an asynchronous callback to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -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&lt;[ValueType](#valuetype)&gt; | Yes| Values of the parameters in the SQL statement.|
| bindArgs | Array&lt;[ValueType](#valuetype)&gt; | Yes| Arguments in the SQL statement.|
| callback | AsyncCallback&lt;[ResultSet](js-apis-data-resultset.md)&gt; | 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 = ?",
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.
Queries data in the RDB store using the specified SQL statement. This API uses a promise to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -1616,7 +1618,7 @@ Queries data using the specified SQL statement. This API uses a promise to retur
| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| sql | string | Yes| SQL statement to run.|
| bindArgs | Array&lt;[ValueType](#valuetype)&gt; | No| Values of the parameters in the SQL statement.|
| bindArgs | Array&lt;[ValueType](#valuetype)&gt; | No| Arguments in the SQL statement.|
**Return value**
| Type| Description|
......@@ -1648,7 +1650,7 @@ Executes an SQL statement that contains specified arguments but returns no value
| -------- | -------- | -------- | -------- |
| sql | string | Yes| SQL statement to run.|
| bindArgs | Array&lt;[ValueType](#valuetype)&gt; | Yes| Arguments in the SQL statement.|
| callback | AsyncCallback&lt;void&gt; | Yes| Callback that returns no value.|
| callback | AsyncCallback&lt;void&gt; | Yes| Callback invoked to return the result.|
**Example**
```js
......@@ -1658,7 +1660,7 @@ rdbStore.executeSql(SQL_CREATE_TABLE, null, function(err) {
console.info("Failed to execute SQL, err: " + err)
return
}
console.info('Create table done.')
console.info('Created table successfully.')
})
```
......@@ -1680,14 +1682,14 @@ Executes an SQL statement that contains specified arguments but returns no value
**Return value**
| Type| Description|
| -------- | -------- |
| Promise&lt;void&gt; | Promise that returns no value.|
| Promise&lt;void&gt; | Promise used to return the result.|
**Example**
```js
const SQL_CREATE_TABLE = "CREATE TABLE IF NOT EXISTS EMPLOYEE (ID INTEGER PRIMARY KEY AUTOINCREMENT, NAME TEXT NOT NULL, AGE INTEGER, SALARY REAL, CODES BLOB)"
let promise = rdbStore.executeSql(SQL_CREATE_TABLE)
promise.then(() => {
console.info('Create table done.')
console.info('Created table successfully.')
}).catch((err) => {
console.info("Failed to execute SQL, err: " + err)
})
......@@ -1785,7 +1787,7 @@ rdbStore.backup("dbBackup.db", function(err) {
console.info('Failed to back up data, err: ' + err)
return
}
console.info('Backup successful.')
console.info('Backed up data successfully.')
})
```
......@@ -1811,7 +1813,7 @@ Backs up an RDB store. This API uses a promise to return the result.
```js
let promiseBackup = rdbStore.backup("dbBackup.db")
promiseBackup.then(()=>{
console.info('Backup successful.')
console.info('Backed up data successfully.')
}).catch((err)=>{
console.info('Failed to back up data, err: ' + err)
})
......@@ -1838,7 +1840,7 @@ rdbStore.restore("dbBackup.db", function(err) {
console.info('Failed to restore data, err: ' + err)
return
}
console.info('Restore successful.')
console.info('Restored data successfully.')
})
```
......@@ -1864,7 +1866,7 @@ Restores an RDB store from a backup file. This API uses a promise to return the
```js
let promiseRestore = rdbStore.restore("dbBackup.db")
promiseRestore.then(()=>{
console.info('Restore successful.')
console.info('Restored data successfully.')
}).catch((err)=>{
console.info('Failed to restore data, err: ' + err)
})
......@@ -1924,7 +1926,7 @@ let promise = rdbStore.setDistributedTables(["EMPLOYEE"])
promise.then(() => {
console.info("Set distributed tables successfully.")
}).catch((err) => {
console.info("Failed to set distributed tables, err: " + err)
console.info('Failed to set distributed tables, err: ' + err)
})
```
......@@ -1932,7 +1934,7 @@ promise.then(() => {
obtainDistributedTableName(device: string, table: string, callback: AsyncCallback&lt;string&gt;): void
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.
**Required permissions**: ohos.permission.DISTRIBUTED_DATASYNC
......@@ -1961,7 +1963,7 @@ rdbStore.obtainDistributedTableName("12345678abcde", "EMPLOYEE", function (err,
obtainDistributedTableName(device: string, table: string): Promise&lt;string&gt;
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.
**Required permissions**: ohos.permission.DISTRIBUTED_DATASYNC
......@@ -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&lt;Array&lt;[string, number]&gt;&gt; | 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&lt;Array&lt;[string, number]&gt;&gt; | 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&lt;Array&lt;[string, number]&gt;&gt; | 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&lt;Array&lt;[string, number]&gt;&gt; | 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. |
**Example**
```js
......
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