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提交 17ecaf51 编写于 作者: A Annie_wang
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Signed-off-by: NAnnie_wang <annie.wangli@huawei.com>
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en/application-dev/database/database-relational-guidelines.md
浏览文件 @ 17ecaf51
......@@ -74,6 +74,8 @@ The RDB provides APIs for inserting, deleting, updating, and querying data in th
| 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.|
### Using Predicates
......@@ -85,34 +87,34 @@ The RDB provides **RdbPredicates** for you to set database operation conditions.
| -------- | -------- | -------- |
| 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 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 | 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 | 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 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): RdbPredicates | 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 | 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 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.|
| 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.|
### Using the Result Set
......@@ -131,8 +133,8 @@ A result set can be regarded as a row of data in the queried results. It allows
| 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 | Checks whether the result set is located in the first row.|
| ResultSet | goToLastRow(): boolean | Checks whether the result set is located in the last row.|
| 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.|
......@@ -162,7 +164,7 @@ You can obtain the distributed table name for a remote device based on the local
| 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, 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.|
**Synchronizing Data Between Devices**
......@@ -172,7 +174,7 @@ You can obtain the distributed table name for a remote device based on the local
| 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**: 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**
......@@ -210,6 +212,16 @@ You can obtain the distributed table name for a remote device based on the local
| 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.|
**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.|
## How to Develop
1. Create an RDB store.
......@@ -270,7 +282,7 @@ You can obtain the distributed table name for a remote device based on the local
const blobType = resultSet.getBlob(resultSet.getColumnIndex("blobType"))
resultSet.close()
})
```
```
4. Set the distributed tables to be synchronized.
......@@ -278,9 +290,9 @@ You can obtain the distributed table name for a remote device based on the local
```js
"requestPermissions":
{
"name": "ohos.permission.DISTRIBUTED_DATASYNC"
}
{
"name": "ohos.permission.DISTRIBUTED_DATASYNC"
}
```
(2) Obtain the required permissions.
......@@ -321,7 +333,7 @@ You can obtain the distributed table name for a remote device based on the local
promise.then((result) => {
console.log('sync done.')
for (let i = 0; i < result.length; i++) {
console.log('device=' + result[i][0] + ' status=' + result[i][1])
console.log('device=' + result[i][0] + 'status=' + result[i][1])
}
}).catch((err) => {
console.log('sync failed')
......@@ -339,7 +351,7 @@ You can obtain the distributed table name for a remote device based on the local
```js
function storeObserver(devices) {
for (let i = 0; i < devices.length; i++) {
console.log('device=' + device[i] + ' data changed')
console.log('device=' + device[i] + 'data changed')
}
}
try {
......@@ -361,8 +373,34 @@ You can obtain the distributed table name for a remote device based on the local
let tableName = rdbStore.obtainDistributedTableName(deviceId, "test");
let resultSet = rdbStore.querySql("SELECT * FROM " + tableName)
```
8. Back up and restore an RDB store.
8. Query data of a remote device.
(1) Construct a predicate object for querying distributed tables, and specify the remote distributed table name and the remote device.
(2) Call the resultSet() API to obtain the result.
The sample code is as follows:
```js
let rdbPredicate = new data_rdb.RdbPredicates('employee')
predicates.greaterThan("id", 0)
let promiseQuery = rdbStore.remoteQuery('12345678abcde', 'employee', rdbPredicate)
promiseQuery.then((resultSet) => {
while (resultSet.goToNextRow()) {
let idx = resultSet.getLong(0);
let name = resultSet.getString(1);
let age = resultSet.getLong(2);
console.info(idx + " " + name + " " + age);
}
resultSet.close();
}).catch((err) => {
console.info("failed to remoteQuery, err: " + err)
})
```
9. Back up and restore an RDB store.
(1) Back up the current RDB store.
......@@ -372,23 +410,17 @@ You can obtain the distributed table name for a remote device based on the local
```js
let promiseBackup = rdbStore.backup("dbBackup.db")
promiseBackup.then(()=>{
promiseBackup.then(() => {
console.info('Backup success.')
}).catch((err)=>{
}).catch((err) => {
console.info('Backup failed, err: ' + err)
})
```
```js
let promiseRestore = rdbStore.restore("dbBackup.db")
promiseRestore.then(()=>{
promiseRestore.then(() => {
console.info('Restore success.')
}).catch((err)=>{
}).catch((err) => {
console.info('Restore failed, err: ' + err)
})
```
## Samples
The following samples are provided for you to better understand the RDB development:
- [`Rdb`: eTS RDB (API8)](https://gitee.com/openharmony/app_samples/tree/master/data/Rdb)
- [`DistributedRdb`: eTS Distributed Relational Database (API8)](https://gitee.com/openharmony/app_samples/tree/master/data/DistributedRdb)
- [Relational Database](https://gitee.com/openharmony/codelabs/tree/master/Data/JSRelationshipData)
en/application-dev/reference/apis/js-apis-data-rdb.md
浏览文件 @ 17ecaf51
......@@ -85,7 +85,7 @@ promise.then(async (rdbStore) => {
deleteRdbStore(context: Context, name: string, callback: AsyncCallback&lt;void&gt;): void
Deletes an RDB store. This API uses an asynchronous callback to return the result.
Deletes an RDB store. This API uses an asynchronous callback to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -211,7 +211,7 @@ predicates.inAllDevices()
equalTo(field: string, value: ValueType): RdbPredicates
Sets the **RdbPredicates** to match the field with data type **ValueType** and value equal to the specified value.
Sets an **RdbPredicates** to match the field with data type **ValueType** and value equal to the specified value.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -238,7 +238,7 @@ predicates.equalTo("NAME", "lisi")
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.
Sets an **RdbPredicates** to match the field with data type **ValueType** and value not equal to the specified value.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -362,7 +362,7 @@ predicates.equalTo("NAME", "Lisa")
contains(field: string, value: string): RdbPredicates
Sets the **RdbPredicates** to match a string containing the specified value.
Sets an **RdbPredicates** to match a string containing the specified value.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -389,7 +389,7 @@ predicates.contains("NAME", "os")
beginsWith(field: string, value: string): RdbPredicates
Sets the **RdbPredicates** to match a string that starts with the specified value.
Sets an **RdbPredicates** to match a string that starts with the specified value.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -416,7 +416,7 @@ predicates.beginsWith("NAME", "os")
endsWith(field: string, value: string): RdbPredicates
Sets the **RdbPredicates** to match a string that ends with the specified value.
Sets an **RdbPredicates** to match a string that ends with the specified value.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -443,7 +443,7 @@ predicates.endsWith("NAME", "se")
isNull(field: string): RdbPredicates
Sets the **RdbPredicates** to match the field whose value is null.
Sets an **RdbPredicates** to match the field whose value is null.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -469,7 +469,7 @@ predicates.isNull("NAME")
isNotNull(field: string): RdbPredicates
Sets the **RdbPredicates** to match the field whose value is not null.
Sets an **RdbPredicates** to match the field whose value is not null.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -495,7 +495,7 @@ predicates.isNotNull("NAME")
like(field: string, value: string): RdbPredicates
Sets the **RdbPredicates** to match a string that is similar to the specified value.
Sets an **RdbPredicates** to match a string that is similar to the specified value.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -522,7 +522,7 @@ predicates.like("NAME", "%os%")
glob(field: string, value: string): RdbPredicates
Sets the **RdbPredicates** to match the specified string.
Sets an **RdbPredicates** to match the specified string.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -549,7 +549,7 @@ predicates.glob("NAME", "?h*g")
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.
Sets an **RdbPredicates** to match the field with data type **ValueType** and value within the specified range.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -577,7 +577,7 @@ predicates.between("AGE", 10, 50)
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.
Sets an **RdbPredicates** to match the field with data type **ValueType** and value out of the specified range.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -604,7 +604,7 @@ predicates.notBetween("AGE", 10, 50)
greaterThan(field: string, value: ValueType): RdbPredicates
Sets the **RdbPredicates** to match the field with data type **ValueType** and value greater than the specified value.
Sets an **RdbPredicates** to match the field with data type **ValueType** and value greater than the specified value.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -631,7 +631,7 @@ predicates.greaterThan("AGE", 18)
lessThan(field: string, value: ValueType): RdbPredicates
Sets the **RdbPredicates** to match the field with data type **ValueType** and value less than the specified value.
Sets an **RdbPredicates** to match the field with data type **ValueType** and value less than the specified value.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -659,7 +659,7 @@ predicates.lessThan("AGE", 20)
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.
Sets an **RdbPredicates** to match the field with data type **ValueType** and value greater than or equal to the specified value.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -687,7 +687,7 @@ predicates.greaterThanOrEqualTo("AGE", 18)
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.
Sets an **RdbPredicates** to match the field with data type **ValueType** and value less than or equal to the specified value.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -715,7 +715,7 @@ predicates.lessThanOrEqualTo("AGE", 20)
orderByAsc(field: string): RdbPredicates
Sets the **RdbPredicates** to match the column with values sorted in ascending order.
Sets an **RdbPredicates** to match the column with values sorted in ascending order.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -742,7 +742,7 @@ predicates.orderByAsc("NAME")
orderByDesc(field: string): RdbPredicates
Sets the **RdbPredicates** to match the column with values sorted in descending order.
Sets an **RdbPredicates** to match the column with values sorted in descending order.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -768,7 +768,7 @@ predicates.orderByDesc("AGE")
distinct(): RdbPredicates
Sets the **RdbPredicates** to filter out duplicate records.
Sets an **RdbPredicates** to filter out duplicate records.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -789,7 +789,7 @@ predicates.equalTo("NAME", "Rose").distinct("NAME")
limitAs(value: number): RdbPredicates
Sets the **RdbPredicates** to specify the maximum number of records.
Sets an **RdbPredicates** to specify the maximum number of records.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -815,7 +815,7 @@ predicates.equalTo("NAME", "Rose").limitAs(3)
offsetAs(rowOffset: number): RdbPredicates
Sets the **RdbPredicates** to specify the start position of the returned result.
Sets an **RdbPredicates** to specify the start position of the returned result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -841,7 +841,7 @@ predicates.equalTo("NAME", "Rose").offsetAs(3)
groupBy(fields: Array&lt;string&gt;): RdbPredicates
Sets the **RdbPredicates** to group rows that have the same value into summary rows.
Sets an **RdbPredicates** to group rows that have the same value into summary rows.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -866,7 +866,7 @@ predicates.groupBy(["AGE", "NAME"])
indexedBy(field: string): RdbPredicates
Sets the **RdbPredicates** object to specify the index column.
Sets an **RdbPredicates** object to specify the index column.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -893,7 +893,7 @@ predicates.indexedBy("SALARY_INDEX")
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.
Sets an **RdbPredicates** to match the field with data type **Array&#60;ValueType&#62;** and value within the specified range.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -921,7 +921,7 @@ predicates.in("AGE", [18, 20])
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.
Sets an **RdbPredicates** to match the field with data type **Array&#60;ValueType&#62;** and value out of the specified range.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -972,12 +972,12 @@ const valueBucket = {
"SALARY": 100.5,
"CODES": new Uint8Array([1, 2, 3, 4, 5]),
}
rdbStore.insert("EMPLOYEE", valueBucket, function (err, ret) {
if (err) {
console.info("Failed to insert data, err: " + err)
return
rdbStore.insert("EMPLOYEE", valueBucket, function (status, rowId) {
if (status) {
console.log("Failed to insert data");
return;
}
console.log("Inserted first row: " + ret)
console.log("Inserted data, rowId = " + rowId);
})
```
......@@ -1010,19 +1010,113 @@ const valueBucket = {
"CODES": new Uint8Array([1, 2, 3, 4, 5]),
}
let promise = rdbStore.insert("EMPLOYEE", valueBucket)
promise.then(async (ret) => {
console.log("Inserted first row: " + ret)
}).catch((err) => {
console.log("Failed to insert data, err: " + err)
promise.then((rowId) => {
console.log("Inserted data, rowId = " + rowId);
}).catch((status) => {
console.log("Failed to insert data");
})
```
### batchInsert<sup>9+</sup>
batchInsert(table: string, values: Array&lt;ValuesBucket&gt;, callback: AsyncCallback&lt;number&gt;):void
Batch inserts data into a table. This API uses an asynchronous callback to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| table | string | Yes| Name of the target table.|
| values | Array&lt;[ValuesBucket](#valuesbucket)&gt; | Yes| An array of data to insert.|
| callback | AsyncCallback&lt;number&gt; | Yes| Callback invoked to return the result. If the operation is successful, the number of inserted data records is returned. Otherwise, **-1** is returned.|
**Example**
```js
const valueBucket1 = {
"NAME": "Lisa",
"AGE": 18,
"SALARY": 100.5,
"CODES": new Uint8Array([1, 2, 3, 4, 5])
}
const valueBucket2 = {
"NAME": "Jack",
"AGE": 19,
"SALARY": 101.5,
"CODES": new Uint8Array([6, 7, 8, 9, 10])
}
const valueBucket3 = {
"NAME": "Tom",
"AGE": 20,
"SALARY": 102.5,
"CODES": new Uint8Array([11, 12, 13, 14, 15])
}
var valueBuckets = new Array(valueBucket1, valueBucket2, valueBucket3);
rdbStore.batchInsert("EMPLOYEE", valueBuckets, function(status, insertNum) {
if (status) {
console.log("bathInsert failed, status = " + status);
return;
}
console.log("bathInsert is successful, the number of values that were inserted = " + insertNum);
})
```
### batchInsert<sup>9+</sup>
batchInsert(table: string, values: Array&lt;ValuesBucket&gt;):Promise&lt;number&gt;
Batch inserts data into a table. This API uses a promise to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| table | string | Yes| Name of the target table.|
| values | Array&lt;[ValuesBucket](#valuesbucket)&gt; | Yes| An array of data to insert.|
**Return value**
| Type| Description|
| -------- | -------- |
| Promise&lt;number&gt; | Promise used to return the result. If the operation is successful, the number of inserted data records is returned. Otherwise, **-1** is returned.|
**Example**
```js
const valueBucket1 = {
"NAME": "Lisa",
"AGE": 18,
"SALARY": 100.5,
"CODES": new Uint8Array([1, 2, 3, 4, 5])
}
const valueBucket2 = {
"NAME": "Jack",
"AGE": 19,
"SALARY": 101.5,
"CODES": new Uint8Array([6, 7, 8, 9, 10])
}
const valueBucket3 = {
"NAME": "Tom",
"AGE": 20,
"SALARY": 102.5,
"CODES": new Uint8Array([11, 12, 13, 14, 15])
}
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);
}).catch((status) => {
console.log("bathInsert failed, status = " + status);
})
```
### update
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 an asynchronous callback to return the result.
Updates data based on the specified **RdbPredicates** object. This API uses an asynchronous callback to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -1057,7 +1151,7 @@ rdbStore.update(valueBucket, predicates, function (err, ret) {
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.
Updates data based on the specified **RdbPredicates** object. This API uses a promise to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -1093,7 +1187,7 @@ promise.then(async (ret) => {
### update<sup>9+</sup>
update(table: string, values: ValuesBucket, predicates: dataSharePredicates.DataSharePredicates, callback: AsyncCallback&lt;number&gt;):void
Updates data in the RDB store based on the specified **DataSharePredicates** object. This API uses an asynchronous callback to return the result.
Updates data based on the specified **DataSharePredicates** object. This API uses an asynchronous callback to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -1128,7 +1222,7 @@ rdbStore.update("EMPLOYEE", valueBucket, predicates, function (err, ret) {
update(table: string, values: ValuesBucket, predicates: dataSharePredicates.DataSharePredicates):Promise&lt;number&gt;
Updates data in the RDB store based on the specified **DataSharePredicates** object. This API uses a promise to return the result.
Updates data based on the specified **DataSharePredicates** object. This API uses a promise to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -1287,7 +1381,7 @@ promise.then((rows) => {
query(predicates: RdbPredicates, columns: Array&lt;string&gt;, callback: AsyncCallback&lt;ResultSet&gt;):void
Queries data in the RDB store based on specified conditions. This API uses an asynchronous callback to return the result.
Queries data from the RDB store based on specified conditions. This API uses an asynchronous callback to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -1317,7 +1411,7 @@ rdbStore.query(predicates, ["ID", "NAME", "AGE", "SALARY", "CODES"], function (e
query(predicates: RdbPredicates, columns?: Array&lt;string&gt;):Promise&lt;ResultSet&gt;
Queries data in the RDB store based on specified conditions. This API uses a promise to return the result.
Queries data from the RDB store based on specified conditions. This API uses a promise to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -1330,7 +1424,7 @@ Queries data in the RDB store based on specified conditions. This API uses a pro
**Return value**
| Type| Description|
| -------- | -------- |
| Promise&lt;[ResultSet](../apis/js-apis-data-resultset.md)&gt; | Promise used to return the result. If the operation is successful, a **ResultSet** object will be returned.|
| Promise&lt;[ResultSet](js-apis-data-resultset.md)&gt; | Promise used to return the result. If the operation is successful, a **ResultSet** object will be returned.|
**Example**
```js
......@@ -1349,7 +1443,7 @@ Queries data in the RDB store based on specified conditions. This API uses a pro
query(table: string, predicates: dataSharePredicates.DataSharePredicates, columns: Array&lt;string&gt;, callback: AsyncCallback&lt;ResultSet&gt;):void
Queries data in the RDB store based on specified conditions. This API uses an asynchronous callback to return the result.
Queries data from the RDB store based on specified conditions. This API uses an asynchronous callback to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -1362,6 +1456,7 @@ Queries data in the RDB store based on specified conditions. This API uses an as
| 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**
```js
import dataSharePredicates from '@ohos.data.dataSharePredicates'
let predicates = new dataSharePredicates.DataSharePredicates()
......@@ -1380,7 +1475,7 @@ rdbStore.query("EMPLOYEE", predicates, ["ID", "NAME", "AGE", "SALARY", "CODES"],
query(table: string, predicates: dataSharePredicates.DataSharePredicates, columns?: Array&lt;string&gt;):Promise&lt;ResultSet&gt;
Queries data in the RDB store based on specified conditions. This API uses a promise to return the result.
Queries data from the RDB store based on specified conditions. This API uses a promise to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -1392,6 +1487,7 @@ Queries data in the RDB store based on specified conditions. This API uses a pro
| columns | Array&lt;string&gt; | No| Columns to query. If this parameter is not specified, the query applies to all columns.|
**Return value**
| Type| Description|
| -------- | -------- |
| Promise&lt;[ResultSet](js-apis-data-resultset.md)&gt; | Promise used to return the result. If the operation is successful, a **ResultSet** object will be returned.|
......@@ -1410,11 +1506,81 @@ promise.then((resultSet) => {
})
```
### remoteQuery<sup>9+</sup>
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.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| 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.|
| 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.|
**Example**
```js
let predicates = new rdb.RdbPredicates('EPLOYEE')
predicates.greaterThan("id", 0)
rdbStore.remoteQuery("deviceId", "EPLOYEE", predicates, function(err, resultSet){
if (err) {
console.info("Failed to remoteQuery, err: " + err)
return
}
console.info("ResultSet column names: " + resultSet.columnNames)
console.info("ResultSet column count: " + resultSet.columnCount)
})
```
### remoteQuery<sup>9+</sup>
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.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
**Parameters**
| Name| Type| Mandatory| Description|
| -------- | -------- | -------- | -------- |
| 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.|
| columns | Array&lt;string&gt; | No| Columns to query. If this parameter is not specified, the query applies to all columns.|
**Return value**
| Type | Description |
| ------------------------------------------------------------ | -------------------------------------------------------- |
| Promise&lt;[ResultSet](js-apis-data-resultset.md#resultset)&gt; | Promise used to return the result. If the operation is successful, a **ResultSet** object will be returned.|
**Example**
```js
let predicates = new rdb.RdbPredicates('EPLOYEE')
predicates.greaterThan("id", 0)
let promise = rdbStore.remoteQuery("deviceId", "EMPLOYEE", predicates)
promise.then((resultSet) => {
console.info("ResultSet column names: " + resultSet.columnNames)
console.info("ResultSet column count: " + resultSet.columnCount)
}).catch((err) => {
console.info("Failed to remoteQuery , err: " + err)
})
```
### querySql<sup>8+</sup>
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 an asynchronous callback to return the result.
Queries data using the specified SQL statement. This API uses an asynchronous callback to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -1442,7 +1608,7 @@ 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 in the RDB store using the specified SQL statement. This API uses a promise to return the result.
Queries data using the specified SQL statement. This API uses a promise to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -1455,7 +1621,7 @@ Queries data in the RDB store using the specified SQL statement. This API uses a
**Return value**
| Type| Description|
| -------- | -------- |
| Promise&lt;[ResultSet](../apis/js-apis-data-resultset.md)&gt; | Promise used to return the result. If the operation is successful, a **ResultSet** object will be returned.|
| Promise&lt;[ResultSet](js-apis-data-resultset.md)&gt; | Promise used to return the result. If the operation is successful, a **ResultSet** object will be returned.|
**Example**
```js
......@@ -1473,7 +1639,7 @@ promise.then((resultSet) => {
executeSql(sql: string, bindArgs: Array&lt;ValueType&gt;, callback: AsyncCallback&lt;void&gt;):void
Runs the SQL statement that contains the specified parameters but does not return a value. This API uses an asynchronous callback to return the result.
Executes an SQL statement that contains specified arguments but returns no value. This API uses an asynchronous callback to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -1481,8 +1647,8 @@ Runs the SQL statement that contains the specified parameters but does not retur
| 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.|
| callback | AsyncCallback&lt;void&gt; | Yes| Callback invoked to return the result.|
| bindArgs | Array&lt;[ValueType](#valuetype)&gt; | Yes| Arguments in the SQL statement.|
| callback | AsyncCallback&lt;void&gt; | Yes| Callback that returns no value.|
**Example**
```js
......@@ -1501,7 +1667,7 @@ rdbStore.executeSql(SQL_CREATE_TABLE, null, function(err) {
executeSql(sql: string, bindArgs?: Array&lt;ValueType&gt;):Promise&lt;void&gt;
Runs the SQL statement that contains the specified parameters but does not return a value. This API uses a promise to return the execution result.
Executes an SQL statement that contains specified arguments but returns no value. This API uses a promise to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -1509,12 +1675,12 @@ Runs the SQL statement that contains the specified parameters but does not 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|
| -------- | -------- |
| Promise&lt;void&gt; | Promise used to return the result.|
| Promise&lt;void&gt; | Promise that returns no value.|
**Example**
```js
......@@ -1544,13 +1710,7 @@ const valueBucket = {
"salary": 100.5,
"blobType": new Uint8Array([1, 2, 3]),
}
rdbStore.insert("test", valueBucket, function (err, ret) {
if (err) {
console.info("Failed to insert data, err: " + err)
return
}
console.log("Inserted data successfully: " + ret)
})
await rdbStore.insert("test", valueBucket)
rdbStore.commit()
```
......@@ -1573,13 +1733,7 @@ const valueBucket = {
"blobType": new Uint8Array([1, 2, 3]),
}
rdbStore.insert("test", valueBucket, function (err, ret) {
if (err) {
console.info("Failed to insert data, err: " + err)
return
}
console.log("Inserted data successfully: " + ret)
})
await rdbStore.insert("test", valueBucket)
rdbStore.commit()
```
......@@ -1603,13 +1757,7 @@ try {
"salary": 100.5,
"blobType": new Uint8Array([1, 2, 3]),
}
rdbStore.insert("test", valueBucket, function (err, ret) {
if (err) {
console.info("Failed to insert data, err: " + err)
return
}
console.log("Inserted data successfully: " + ret)
})
await rdbStore.insert("test", valueBucket)
rdbStore.commit()
} catch (e) {
rdbStore.rollBack()
......@@ -1673,7 +1821,7 @@ promiseBackup.then(()=>{
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.
Restores an RDB store from a backup file. This API uses an asynchronous callback to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -1698,7 +1846,7 @@ rdbStore.restore("dbBackup.db", function(err) {
restore(srcName:string): Promise&lt;void&gt;
Restores an RDB store using a backup file. This API uses a promise to return the result.
Restores an RDB store from a backup file. This API uses a promise to return the result.
**System capability**: SystemCapability.DistributedDataManager.RelationalStore.Core
......@@ -1726,7 +1874,7 @@ promiseRestore.then(()=>{
setDistributedTables(tables: Array&lt;string&gt;, callback: AsyncCallback&lt;void&gt;): void
Sets a list of distributed tables. This API uses an asynchronous callback to return the result.
Sets distributed tables. This API uses an asynchronous callback to return the result.
**Required permissions**: ohos.permission.DISTRIBUTED_DATASYNC
......@@ -1747,14 +1895,14 @@ rdbStore.setDistributedTables(["EMPLOYEE"], function (err) {
}
console.info('Set distributed tables successfully.')
})
```
```
### setDistributedTables<sup>8+</sup>
setDistributedTables(tables: Array&lt;string&gt;): Promise&lt;void&gt;
Sets a list of distributed tables. This API uses a promise to return the result.
Sets distributed tables. This API uses a promise to return the result.
**Required permissions**: ohos.permission.DISTRIBUTED_DATASYNC
......@@ -1784,7 +1932,7 @@ 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 database 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. 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.
**Required permissions**: ohos.permission.DISTRIBUTED_DATASYNC
......@@ -1813,7 +1961,7 @@ 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 database 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. 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.
**Required permissions**: ohos.permission.DISTRIBUTED_DATASYNC
......@@ -1947,7 +2095,7 @@ try {
off(event:'dataChange', type: SubscribeType, observer: Callback&lt;Array&lt;string&gt;&gt;): void
Deletes the specified observer of the RDB store. This API uses a callback to return the result.
Unregisters the observer of the specified type from the RDB store. This API uses a callback to return the result.
**Required permissions**: ohos.permission.DISTRIBUTED_DATASYNC
......
en/device-dev/subsystems/subsys-data-relational-database-guide.md
浏览文件 @ 17ecaf51
......@@ -71,7 +71,7 @@ You can use the APIs provided by the RDB to insert, delete, update, and query lo
**Table 5** API for deleting data
| Class| API| Description|
| ---- | ---- | ---- |
| RdbStore | int Delete(int &deletedRows, const AbsRdbPredicates &predicates) | Deletes data.<br> - **deletedRows**: number of rows to delete.<br> - **predicates**: table name and conditions for deleting the data. **AbsRdbPredicates** has the following classes:<br> - **RdbPredicates**: specifies conditions by calling its methods, such as **equalTo**.<br> - **RawRdbPredicates**: specifies the table name, **whereClause**, and **whereArgs** only. |
| RdbStore | int Delete(int &deletedRows, const AbsRdbPredicates &predicates) | Deletes data.<br> - **deletedRows**: number of rows to delete.<br> - **predicates**: table name and conditions for deleting the data. **AbsRdbPredicates** has the following classes:<br> - **RdbPredicates**: specifies query conditions by calling its methods, such as **equalTo**.<br> - **RawRdbPredicates**: specifies the table name, **whereClause**, and **whereArgs** only. |
- Updating data
......@@ -123,7 +123,7 @@ Call **bool SetDistributedTables()** to set distributed tables for data operatio
**Table 9** API for setting distributed tables
| Class| API| Description|
| ---- | ---- | ---- |
| RdbStore | bool SetDistributedTables(const std::vector<std::string>& tables) | Sets distributed tables.<br> - **tables**: names of the distributed tables to set.
| RdbStore | bool SetDistributedTables(const std::vector<std::string>& tables) | Sets distributed tables.<br> **tables**: names of the distributed tables to set. |
### Obtaining the Distributed Table Name for a Remote Device
......@@ -132,28 +132,28 @@ You can obtain the distributed table name for a remote device based on the local
**Table 10** API for obtaining the distributed table name of a remote device
| Class| API| Description|
| ---- | ---- | ---- |
| RdbStore | std::string ObtainDistributedTableName(const std::string& device, const std::string& table) | Obtains the distributed table name of 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.<br> - **device**: ID of the remote device. <br>- **table**: name of the local table.
| RdbStore | std::string ObtainDistributedTableName(const std::string& device, const std::string& table) | Obtains the distributed table name of 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.<br> - **device**: ID of the remote device. <br>- **table**: name of the local table.|
### Synchronizing Data Between Devices
**Table 11** API for synchronizing data between devices
| Class| API| Description|
| ---- | ---- | ---- |
| RdbStore | bool Sync(const SyncOption& option, const AbsRdbPredicates& predicate, const SyncCallback& callback) | Synchronizes data between devices. <br>- **option**: synchronization options, which include **mode** and **isBlock**. **mode** specifies how data is synchronized. The value **push** means to push data from the local device to the remote device; the value **pull** means to pull data from the remote device to the local device. **isBlock** specifies whether the invocation of this function is blocked. <br>- **callback**: callback used to return the result.
| RdbStore | bool Sync(const SyncOption& option, const AbsRdbPredicates& predicate, const SyncCallback& callback) | Synchronizes data between devices. <br/>- **option**: synchronization options, which include **mode** and **isBlock**. **mode** specifies how data is synchronized. The value **push** means to push data from the local device to the remote device; the value **pull** means to pull data from the remote device to the local device. **isBlock** specifies whether the invocation of this function is blocked. <br>- **callback**: callback used to return the result. |
### Registering an RDB Store Observer
**Table 12** API for registering an observer
| Class| API| Description|
| ---- | ---- | ---- |
| RdbStore | bool Subscribe(const SubscribeOption& option, RdbStoreObserver *observer) | Registers an observer for this RDB store to listen for distributed data changes. When data in the RDB store changes, a callback will be invoked to return the data changes. <br>- **option**: subscription type.<br>- **observer**: observer that listens for data changes in the RDB store.
| RdbStore | bool Subscribe(const SubscribeOption& option, RdbStoreObserver *observer) | Registers an observer for this RDB store to listen for distributed data changes. When data in the RDB store changes, a callback will be invoked to return the data changes. <br/>- **option**: subscription type.<br>- **observer**: observer that listens for data changes in the RDB store. |
### Unregistering an RDB Store Observer
**Table 13** API for unregistering an observer
| Class| API| Description|
| ---- | ---- | ---- |
| RdbStore | bool UnSubscribe(const SubscribeOption& option, RdbStoreObserver *observer) | Unregisters the observer of the specified type. <br>- **option**: subscription type to unregister.<br>- **observer**: observer to unregister.
| RdbStore | bool UnSubscribe(const SubscribeOption& option, RdbStoreObserver *observer) | Unregisters the observer of the specified type. <br/>- **option**: subscription type to unregister.<br>- **observer**: observer to unregister. |
### Backing Up and Restoring an RDB Store
......@@ -167,7 +167,9 @@ You can use the APIs provided by **rdbStore** to back up and restore local datab
| Class| API| Description|
| ---- | ---- | ---- |
| RdbStore | int Backup(const std::string databasePath, const std::vector&lt;uint8_t&gt; destEncryptKey) | Backs up the current database file.<br> - **databasePath**: name or path of the backup file to generate.<br> - **destEncryptKey**: key used to encrypt the RDB store. Currently, only non-encrypted RDB stores can be backed up. |
| RdbStore | int Backup(const std::string databasePath, const std::vector&lt;uint8_t&gt; destEncryptKey) | Backs up the current database file.<br>- **databasePath**: name or path of the backup file to generate.<br>- **destEncryptKey**: key used to encrypt the RDB store. Currently, only non-encrypted RDB stores can be backed up. |
- Restoring an RDB store
......@@ -179,6 +181,18 @@ You can use the APIs provided by **rdbStore** to back up and restore local datab
| ---- | ---- | ---- |
| RdbStore | int Restore(const std::string backupPath, const std::vector&lt;uint8_t&gt; &newKey) | Restore an RDB store.<br> - **backupPath**: name or path of the backup file.<br> - **newKey**: key used to encrypt the RDB store. Currently, only non-encrypted RDB stores can be restored. |
### Transaction
A transaction is a unit of work performed in a database. If a transaction is successful, **0** is returned. Otherwise, an error code is returned.
Table 16 Transaction APIs
| Class| API| Description|
| ---- | ---- | ---- |
| RdbStore | int BeginTransaction() | Starts a transaction.|
| RdbStore | int Commit() | Commits the changes.|
| RdbStore | int RollBack() | Rolls back the changes.|
## Constraints
None.
......@@ -257,7 +271,7 @@ None.
4. Set the distributed tables to be synchronized.
a. Call the **SetDistributedTables()** method to set the distributed tables to be synchronized.
Call the **SetDistributedTables()** method to set the distributed tables to be synchronized.
The sample code is as follows:
......
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