Skip to content

D
Docs

OpenHarmony / Docs
大约 2 年 前同步成功

通知 161
Star 293
Fork 28
D
Docs
未验证 提交 38d7baa6 编写于 作者: O openharmony_ci 提交者： Gitee
浏览文件
操作

!10257 [翻译完成】#I5Q9DY 

Merge pull request !10257 from Annie_wang/PR9222
上级 cc3045e9 60616bca
隐藏空白更改
内联 并排
Showing with 78 addition and 48 deletion
en/application-dev/database/database-mdds-guidelines.md
浏览文件 @ 38d7baa6
......@@ -6,6 +6,7 @@ The Distributed Data Service (DDS) implements synchronization of application dat
## Available APIs
For details about the APIs related to distributed data, see [Distributed Data Management](../reference/apis/js-apis-distributed-data.md).
......@@ -13,13 +14,13 @@ For details about the APIs related to distributed data, see [Distributed Data Ma
| API | Description |
| ------------------------------------------------------------ | ----------------------------------------------- |
| createKVManager(config:KVManagerConfig,callback:AsyncCallback&lt;KVManager&gt;):void<br>createKVManager(config:KVManagerConfig):Promise&lt;KVManager> | Creates a **KVManager** object for database management.|
| getKVStore&lt;TextendsKVStore&gt;(storeId:string,options:Options,callback:AsyncCallback&lt;T&gt;):void<br>getKVStore&lt;TextendsKVStore&gt;(storeId:string,options:Options):Promise&lt;T&gt; | Obtains a KV store with the specified **Options** and **storeId**.|
| put(key:string,value:Uint8Array\|string\|number\|boolean,callback:AsyncCallback&lt;void&gt;):void<br>put(key:string,value:Uint8Array\|string\|number\|boolean):Promise&lt;void> | Inserts and updates data. |
| delete(key:string,callback:AsyncCallback&lt;void&gt;):void<br>delete(key:string):Promise&lt;void> | Deletes data. |
| get(key:string,callback:AsyncCallback&lt;Uint8Array\|string\|boolean\|number&gt;):void<br>get(key:string):Promise&lt;Uint8Array\|string\|boolean\|number> | Queries data. |
| on(event:'dataChange',type:SubscribeType,observer:Callback&lt;ChangeNotification&gt;):void<br>on(event:'syncComplete',syncCallback:Callback&lt;Array&lt;[string,number]&gt;&gt;):void | Subscribes to data changes in the KV store. |
| sync(deviceIdList:string[],mode:SyncMode,allowedDelayMs?:number):void | Triggers database synchronization in manual mode. |
| createKVManager(config: KVManagerConfig, callback: AsyncCallback&lt;KVManager&gt;): void<br>createKVManager(config: KVManagerConfig): Promise&lt;KVManager> | Creates a **KVManager** object for database management.|
| getKVStore&lt;TextendsKVStore&gt;(storeId: string, options: Options, callback: AsyncCallback&lt;T&gt;): void<br>getKVStore&lt;TextendsKVStore&gt;(storeId: string, options: Options): Promise&lt;T&gt; | Obtains a KV store with the specified **Options** and **storeId**.|
| put(key: string, value: Uint8Array\|string\|number\|boolean, callback: AsyncCallback&lt;void&gt;): void<br>put(key: string, value: Uint8Array\|string\|number\|boolean): Promise&lt;void> | Inserts and updates data. |
| delete(key: string, callback: AsyncCallback&lt;void&gt;): void<br>delete(key: string): Promise&lt;void> | Deletes data. |
| get(key: string, callback: AsyncCallback&lt;Uint8Array\|string\|boolean\|number&gt;): void<br>get(key: string): Promise&lt;Uint8Array\|string\|boolean\|number> | Queries data. |
| on(event: 'dataChange', type: SubscribeType, observer: Callback&lt;ChangeNotification&gt;): void<br>on(event: 'syncComplete', syncCallback: Callback&lt;Array&lt;[string,number]&gt;&gt;): void | Subscribes to data changes in the KV store. |
| sync(deviceIdList: string[], mode: SyncMode, allowedDelayMs?: number): void | Triggers database synchronization in manual mode. |
......@@ -29,19 +30,50 @@ For details about the APIs related to distributed data, see [Distributed Data Ma
The following uses a single KV store as an example to describe the development procedure.
1. Import the distributed data module.
```js
import distributedData from '@ohos.data.distributedData';
```
2. Apply for the required permission if data synchronization is required.
2. Create a **KvManager** instance based on the specified **KvManagerConfig** object.
(1) Create a **KvManagerConfig** object based on the application context.
You need to configure the request permission in the **config.json** file. The sample code is as follows:
```json
{
"module": {
"reqPermissions": [
{
"name": "ohos.permission.DISTRIBUTED_DATASYNC"
}
]
}
}
```
This permission must also be granted by the user when the application is started for the first time. The sample code is as follows:
```js
import featureAbility from '@ohos.ability.featureAbility';
function grantPermission() {
console.info('grantPermission');
let context = featureAbility.getContext();
context.requestPermissionsFromUser(['ohos.permission.DISTRIBUTED_DATASYNC'], 666, function (result) {
console.info(`result.requestCode=${result.requestCode}`)
})
console.info('end grantPermission');
}
grantPermission();
```
3. Create a **KvManager** instance based on the specified **KvManagerConfig** object.
1. Create a **kvManagerConfig** object based on the application context.
2. Create a **kvManager** instance.
(2) Create a **KvManager** instance.
The sample code is as follows:
```
```js
let kvManager;
try {
const kvManagerConfig = {
......@@ -63,13 +95,11 @@ The following uses a single KV store as an example to describe the development p
console.log("An unexpected error occurred. Error:" + e);
}
```
3. Create and obtain a single KV store.
(1) Declare the ID of the single KV store to create.
4. Create and obtain a single KV store.
(2) Create a single KV store. You are advised to disable automatic synchronization (**autoSync:false**) and call **sync** when a synchronization is required.
1. Declare the ID of the single KV store to create.
2. Create a single KV store. You are advised to disable automatic synchronization (`autoSync:false`) and call `sync` when a synchronization is required.
The sample code is as follows:
```js
......@@ -99,8 +129,9 @@ The following uses a single KV store as an example to describe the development p
> **NOTE**
>
> For data synchronization between networked devices, you are advised to open the distributed KV store during application startup to obtain the database handle. With this database handle (`kvStore` in this example), you can perform operations, such as inserting data into the KV store, without creating the KV store repeatedly during the lifecycle of the handle.
5. Subscribe to changes in the distributed data.
4. Subscribe to changes in the distributed data.<br/>
The following is the sample code for subscribing to the data changes of a single KV store:
```js
kvStore.on('dataChange', distributedData.SubscribeType.SUBSCRIBE_TYPE_ALL, function (data) {
......@@ -108,11 +139,10 @@ The following uses a single KV store as an example to describe the development p
});
```
5. Write data to the single KV store.
6. Write data to the single KV store.
(1) Construct the key and value to be written into the single KV store.
(2) Write key-value pairs into the single KV store.
1. Construct the `Key` and `Value` to be written into the single KV store.
2. Write key-value pairs into the single KV store.
The following is the sample code for writing key-value pairs of the string type into the single KV store:
......@@ -132,11 +162,10 @@ The following uses a single KV store as an example to describe the development p
}
```
6. Query data in the single KV store.
(1) Construct the key to be queried from the single KV store.
7. Query data in the single KV store.
(2) Query data from the single KV store.
1. Construct the `Key` to be queried from the single KV store.
2. Query data from the single KV store.
The following is the sample code for querying data of the string type from the single KV store:
```js
......@@ -158,7 +187,8 @@ The following uses a single KV store as an example to describe the development p
}
```
7. Synchronize data to other devices.<br/>
8. Synchronize data to other devices.
Select the devices in the same network and the synchronization mode to synchronize data.
> **NOTE**
......
en/application-dev/database/database-relational-guidelines.md
浏览文件 @ 38d7baa6
......@@ -16,8 +16,8 @@ The table below describes the APIs available for creating and deleting an RDB st
| API| Description|
| -------- | -------- |
|getRdbStore(config:StoreConfig,version:number):Promise&lt;RdbStore&gt; | Obtains an RDB store. This API uses a promise to return the result. You can set parameters for the RDB store based on service requirements and call APIs to perform data operations.<br>- **config**: configuration of the RDB store.<br>- **version**: version of the RDB store.|
| deleteRdbStore(name:string):Promise&lt;void&gt; | Deletes an RDB store. This API uses a promise to return the result.<br>- **name**: name of the RDB store to delete.|
|getRdbStore(config: StoreConfig, version: number): Promise&lt;RdbStore&gt; | Obtains an RDB store. This API uses a promise to return the result. You can set parameters for the RDB store based on service requirements and call APIs to perform data operations.<br>- **config**: configuration of the RDB store.<br>- **version**: version of the RDB store.|
| deleteRdbStore(name: string): Promise&lt;void&gt; | Deletes an RDB store. This API uses a promise to return the result.<br>- **name**: name of the RDB store to delete.|
### Managing Data in an RDB Store
......@@ -31,7 +31,7 @@ The **RDB** module provides APIs for inserting, deleting, updating, and querying
| Class| API| Description|
| -------- | -------- | -------- |
| RdbStore | insert(name:string,values:ValuesBucket):Promise&lt;number&gt; | Inserts a row of data into a table. This API uses a promise to return the result.<br>If the operation is successful, the row ID will be returned; otherwise, **-1** will be returned.<br>- **name**: name of the target table.<br>- **values**: data to be inserted into the table.|
| RdbStore | insert(name: string, values: ValuesBucket): Promise&lt;number&gt; | Inserts a row of data into a table. This API uses a promise to return the result.<br>If the operation is successful, the row ID will be returned; otherwise, **-1** will be returned.<br>- **name**: name of the target table.<br>- **values**: data to be inserted into the table.|
- **Updating Data**
......@@ -41,7 +41,7 @@ The **RDB** module provides APIs for inserting, deleting, updating, and querying
| Class| API| Description|
| -------- | -------- | -------- |
| RdbStore | update(values:ValuesBucket,rdbPredicates:RdbPredicates):Promise\<number> | Updates data based on the specified **RdbPredicates** object. This API uses a promise to return the result.<br>Return value: number of rows updated.<br>- **values**: data to update, which is stored in **ValuesBucket**.<br>- **rdbPredicates**: conditions for updating data.|
| RdbStore | update(values: ValuesBucket, rdbPredicates: RdbPredicates): Promise\<number> | Updates data based on the specified **RdbPredicates** object. This API uses a promise to return the result.<br>Return value: number of rows updated.<br>- **values**: data to update, which is stored in **ValuesBucket**.<br>- **rdbPredicates**: conditions for updating data.|
- **Deleting Data**
......@@ -51,7 +51,7 @@ The **RDB** module provides APIs for inserting, deleting, updating, and querying
| Class| API| Description|
| -------- | -------- | -------- |
| RdbStore | delete(rdbPredicates:RdbPredicates):Promise\<number> | Deletes data from the RDB store based on the specified **RdbPredicates** object. This API uses a promise to return the result.<br>Return value: number of rows updated.<br>- **rdbPredicates**: conditions for deleting data.|
| RdbStore | delete(rdbPredicates: RdbPredicates): Promise\<number> | Deletes data from the RDB store based on the specified **RdbPredicates** object. This API uses a promise to return the result.<br>Return value: number of rows updated.<br>- **rdbPredicates**: conditions for deleting data.|
- **Querying data**
......@@ -64,8 +64,8 @@ The **RDB** module provides APIs for inserting, deleting, updating, and querying
| Class| API| Description|
| -------- | -------- | -------- |
| RdbStore | query(rdbPredicates:RdbPredicates,columns:Array):Promise&lt;ResultSet&gt; | Queries data from the RDB store based on specified conditions. This API uses a promise to return the result.<br>- **rdbPredicates**: conditions for querying data.<br>- **columns**: columns to query. If this parameter is not specified, the query applies to all columns.|
| RdbStore | 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 | query(rdbPredicates: RdbPredicates, columns: Array): Promise&lt;ResultSet&gt; | Queries data from the RDB store based on specified conditions. This API uses a promise to return the result.<br>- **rdbPredicates**: conditions for querying data.<br>- **columns**: columns to query. If this parameter is not specified, the query applies to all columns.|
| RdbStore | 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.|
### Using Predicates
......@@ -77,11 +77,11 @@ The table below lists common predicates. For more information about predicates,
| Class| API| Description|
| -------- | -------- | -------- |
| RdbPredicates | equalTo(field:string,value:ValueType):RdbPredicates | Sets an **RdbPredicates** object 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 created.|
| RdbPredicates | notEqualTo(field:string,value:ValueType):RdbPredicates | Sets an **RdbPredicates** object 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 created.|
| RdbPredicates | or():RdbPredicates | Adds the OR condition to the **RdbPredicates** object.<br>- **RdbPredicates**: **RdbPredicates** with the OR condition.|
| RdbPredicates | and():RdbPredicates | Adds the AND condition to the **RdbPredicates** object.<br>- **RdbPredicates**: **RdbPredicates** with the AND condition.|
| RdbPredicates | contains(field:string,value:string):RdbPredicats | Sets an **RdbPredicates** object to match a string that contains the specified value.<br>- **field**: column name in the database table.<br>- **value**: value to match the **RdbPredicates**.<br>- **RdbPredicates**: **RdbPredicates** object created.|
| RdbPredicates | equalTo(field: string, value: ValueType): RdbPredicates | Sets an **RdbPredicates** object 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 created.|
| RdbPredicates | notEqualTo(field: string, value: ValueType): RdbPredicates | Sets an **RdbPredicates** object 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 created.|
| RdbPredicates | or(): RdbPredicates | Adds the OR condition to the **RdbPredicates** object.<br>- **RdbPredicates**: **RdbPredicates** with the OR condition.|
| RdbPredicates | and(): RdbPredicates | Adds the AND condition to the **RdbPredicates** object.<br>- **RdbPredicates**: **RdbPredicates** with the AND condition.|
| RdbPredicates | contains(field: string, value: string): RdbPredicats | Sets an **RdbPredicates** object to match a string that contains the specified value.<br>- **field**: column name in the database table.<br>- **value**: value to match the **RdbPredicates**.<br>- **RdbPredicates**: **RdbPredicates** object created.|
### Using the Result Set
......@@ -97,12 +97,12 @@ For details about how to use result set APIs, see [Result Set](../reference/apis
| 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.|
| 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.|
......@@ -148,7 +148,7 @@ You can obtain the distributed table name for a remote device based on the local
| Class| API| Description|
| -------- | -------- | -------- |
| RdbStore |off(event:'dataChange', type: SubscribeType, observer: Callback<Array\<string>>): void;| Unregisters the observer of the specified type for the RDB store. This API uses a callback to return the result.<br>- **type**: subscription type. **SUBSCRIBE_TYPE_REMOTE** means to subscribe to remote data changes.<br>- **observer**: observer to unregister.|
| RdbStore |off(event:'dataChange', type: SubscribeType, observer: Callback<Array\<string>>): void;| Unregisters the observer of the specified type for the RDB store. This method 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.|
## How to Develop
......
Markdown is supported
0% 或 .
You are about to add 0 people to the discussion. Proceed with caution.
先完成此消息的编辑！
想要评论请 注册 或