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!6861 【翻译完成】#I5E46V 

Merge pull request !6861 from Annie_wang/PR5875
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en/application-dev/database/database-distributedobject-guidelines.md
浏览文件 @ 584d87ba
......@@ -7,6 +7,8 @@ The distributed data objects allow data across devices to be processed like loca
## Available APIs
For details about the APIs related to the distributed data object, see [Distributed Data Object](../reference/apis/js-apis-data-distributedobject.md).
### Creating a Distributed Data Object Instance
Call **createDistributedObject()** to create a distributed data object instance. You can specify the attributes of the instance in **source**.
......@@ -15,7 +17,7 @@ Call **createDistributedObject()** to create a distributed data object instance.
**Table 1** API for creating a distributed data object instance
| Package| API| Description|
| -------- | -------- | -------- |
| ohos.data.distributedDataObject| createDistributedObject(source: object): DistributedObject | Creates a distributed data object instance for data operations.<br>-&nbsp;**source**: attributes of the **distributedObject** set.<br>-&nbsp;**DistributedObject**: returns the distributed object created.|
| ohos.data.distributedDataObject| createDistributedObject(source: object): DistributedObject | Creates a distributed data object instance for data operations.<br>- **source**: attributes of the **distributedObject** set.<br>- **DistributedObject**: returns the distributed object created.|
### Generating a Session ID
......@@ -33,16 +35,16 @@ Call **setSessionId()** to set a session ID for a distributed data object. The s
**Table 3** API for setting a session ID
| Class| API| Description|
| -------- | -------- | -------- |
| DistributedDataObject | setSessionId(sessionId?: string): boolean | Sets a session ID for distributed data objects.<br>&nbsp;**sessionId**: session ID of a distributed object in a trusted network. To remove a distributed data object from the network, set this parameter to "" or leave it empty.|
| DistributedDataObject | setSessionId(sessionId?: string): boolean | Sets a session ID for distributed data objects.<br> **sessionId**: session ID of a distributed object in a trusted network. To remove a distributed data object from the network, set this parameter to "" or leave it empty.|
### Observing Data Changes
Call **on()** to subscribe to data changes of a distributed data object. When the data changes, a callback will be invoked to return the data changes. You can use **off()** to unsubscribe from the data changes.
**Table 4** APIs for observing data changes of a distributed data object
| Class| API| Description|
| Class| API| Description|
| -------- | -------- | -------- |
| DistributedDataObject| on(type: 'change', callback: Callback<{ sessionId: string, fields: Array&lt;string&gt; }>): void | Subscribes to data changes.|
| DistributedDataObject| on(type: 'change', callback: Callback<{ sessionId: string, fields: Array&lt;string&gt; }>): void | Subscribes to data changes.|
| DistributedDataObject| off(type: 'change', callback?: Callback<{ sessionId: string, fields: Array&lt;string&gt; }>): void | Unsubscribes from data changes. **Callback**: specifies callback used to return changes of the distributed data object. If this parameter is not specified, all callbacks related to data changes will be unregistered.|
### Observing Online or Offline Status
......@@ -67,13 +69,13 @@ The saved data will be released in the following cases:
- The application has been uninstalled.
- Data is successfully restored.
**Table 6** APIs for saving a distributed data object and revoking the saving
**Table 6** APIs for saving a distributed data object and revoking the saving operation
| Class| API| Description|
| -------- | -------- | -------- |
| DistributedDataObject | save(deviceId: string): Promise&lt;SaveSuccessResponse&gt; | Saves a distributed data object. This API uses a promise to return the result.|
| DistributedDataObject| save(deviceId: string, callback: AsyncCallback&lt;SaveSuccessResponse&gt;): void | Saves a distributed data object. This API uses an asynchronous callback to return the result.|
| DistributedDataObject | revokeSave(callback: AsyncCallback&lt;RevokeSaveSuccessResponse&gt;): void | Revokes the data saving operation. This API uses an asynchronous callback to return the result. |
| DistributedDataObject| revokeSave(): Promise&lt;RevokeSaveSuccessResponse&gt; | Revokes the data saving operation. This API uses a promise to return the result. |
| DistributedDataObject | revokeSave(callback: AsyncCallback&lt;RevokeSaveSuccessResponse&gt;): void | Revokes the data saving operation. This API uses an asynchronous callback to return the result.|
| DistributedDataObject| revokeSave(): Promise&lt;RevokeSaveSuccessResponse&gt; | Revokes the data saving operation. This API uses a promise to return the result.|
## How to Develop
......@@ -157,7 +159,7 @@ The following example shows how to implement a distributed data object synchroni
local_object.on("change", this.changeCallback.bind(this));
```
6. Modify object attributes. <br>The object attributes support basic data types (such as number, Boolean, and string) and complex data types (array and nested basic types).
6. Modify object attributes. <br>The object attributes support basic data types (such as number, Boolean, and string) and complex data types (array and nested basic types).
The sample code is as follows:
```js
......@@ -205,41 +207,39 @@ The following example shows how to implement a distributed data object synchroni
10. Save a distributed data object and revoke the data saving operation.
- Callback
```js
// Save a distributed data object.
local_object.save("local", (result, data)=>{
console.log("save callback");
console.info("save sessionId " + data.sessionId);
console.info("save version " + data.version);
console.info("save deviceId " + data.deviceId);
});
// Revoke the data saving operation.
local_object.revokeSave((result, data) =>{
console.log("revokeSave callback");
console.info("revokeSave sessionId " + data.sessionId);
});
```
- Promise
```js
// Save a distributed data object.
g_object.save("local").then((result)=>{
console.info("save sessionId " + result.sessionId);
console.info("save version " + result.version);
console.info("save deviceId " + result.deviceId);
}, (result)=>{
console.info("save local failed.");
});
// Revoke the data saving operation.
g_object.revokeSave().then((result)=>{
console.info("revokeSave success.");
}, (result)=>{
console.info("revokeSave failed.");
});
```
11. Unsubscribe from the status changes of the distributed data object. <br>You can specify the callback to unregister. If you do not specify the callback, this API unregister all callbacks of this distributed data object.
```js
// Save a distributed data object.
local_object.save("local", (result, data)=>{
console.log("save callback");
console.info("save sessionId " + data.sessionId);
console.info("save version " + data.version);
console.info("save deviceId " + data.deviceId);
});
// Revoke the data saving operation.
local_object.revokeSave((result, data) =>{
console.log("revokeSave callback");
console.info("revokeSave sessionId " + data.sessionId);
});
```
- Promise
```js
// Save a distributed data object.
g_object.save("local").then((result)=>{
console.info("save sessionId " + result.sessionId);
console.info("save version " + result.version);
console.info("save deviceId " + result.deviceId);
}, (result)=>{
console.info("save local failed.");
});
// Revoke the data saving operation.
g_object.revokeSave().then((result)=>{
console.info("revokeSave success.");
}, (result)=>{
console.info("revokeSave failed.");
});
```
11. Unsubscribe from the status changes of the distributed data object. <br>You can specify the callback to unregister. If you do not specify the callback, this API unregisters all callbacks of this distributed data object.
The sample code is as follows:
```js
......
en/application-dev/database/database-mdds-guidelines.md
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......@@ -7,19 +7,21 @@ 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).
The table below describes the APIs provided by the OpenHarmony DDS module.
**Table 1** APIs provided by the DDS
| Category | API | Description |
| -------- | --- | ----------- |
| Creating a distributed database | createKVManager(config: KVManagerConfig, callback: AsyncCallback&lt;KVManager&gt;): void<br>createKVManager(config: KVManagerConfig): Promise&lt;KVManager> | Creates a **KVManager** object for database management.|
| Obtaining a distributed KV store | getKVStore&lt;T extends KVStore&gt;(storeId: string, options: Options, callback: AsyncCallback&lt;T&gt;): void<br>getKVStore&lt;T extends KVStore&gt;(storeId: string, options: Options): Promise&lt;T&gt; | Obtains the KV store with the specified **Options** and **storeId**. |
| Managing data in a distributed KV store | 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. |
| Category | API | Description |
| ------------ | ------------- | ------------- |
| Creating a distributed database| createKVManager(config: KVManagerConfig, callback: AsyncCallback&lt;KVManager&gt;): void<br>createKVManager(config: KVManagerConfig): Promise&lt;KVManager> | Creates a **KVManager** object for database management.|
| Obtaining a distributed KV store| getKVStore&lt;T extends KVStore&gt;(storeId: string, options: Options, callback: AsyncCallback&lt;T&gt;): void<br>getKVStore&lt;T extends KVStore&gt;(storeId: string, options: Options): Promise&lt;T&gt; | Obtains the KV store with the specified **Options** and **storeId**.|
| Managing data in a distributed KV store| 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.|
| Managing data in a distributed KV store| delete(key: string, callback: AsyncCallback&lt;void&gt;): void<br>delete(key: string): Promise&lt;void> | Deletes data. |
| Managing data in a distributed KV store | get(key: string, callback: AsyncCallback&lt;Uint8Array \| string \| boolean \| number&gt;): void<br>get(key: string): Promise&lt;Uint8Array \| string \| boolean \| number> | Queries data. |
| Subscribing to changes in the distributed 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. |
| Synchronizing data across devices | sync(deviceIdList: string[], mode: SyncMode, allowedDelayMs?: number): void | Triggers database synchronization in manual mode. |
| Managing data in a distributed KV store| get(key: string, callback: AsyncCallback&lt;Uint8Array \| string \| boolean \| number&gt;): void<br>get(key: string): Promise&lt;Uint8Array \| string \| boolean \| number> | Queries data. |
| Subscribing to changes in the distributed 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.|
| Synchronizing data across devices| sync(deviceIdList: string[], mode: SyncMode, allowedDelayMs?: number): void | Triggers database synchronization in manual mode. |
......@@ -29,14 +31,13 @@ The table below describes the APIs provided by the OpenHarmony DDS module.
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. 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.
(1) Create a **KvManagerConfig** object based on the application context.
(2) Create a **KvManager** instance.
The sample code is as follows:
```js
......@@ -63,8 +64,8 @@ The following uses a single KV store as an example to describe the development p
```
3. Create and obtain a single KV store.
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.
(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
......@@ -91,12 +92,11 @@ The following uses a single KV store as an example to describe the development p
}
```
> ![icon-note.gif](../public_sys-resources/icon-note.gif) **NOTE**<br/>
> ![icon-note.gif](public_sys-resources/icon-note.gif) **NOTE**<br/>
> 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.
4. Subscribe to changes in the distributed data.<br/>
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) {
console.log("dataChange callback call data: " + JSON.stringify(data));
......@@ -104,8 +104,8 @@ The following uses a single KV store as an example to describe the development p
```
5. 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:
......@@ -126,11 +126,10 @@ 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.
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
const KEY_TEST_STRING_ELEMENT = 'key_test_string';
const VALUE_TEST_STRING_ELEMENT = 'value-test-string';
......@@ -178,3 +177,7 @@ The following uses a single KV store as an example to describe the development p
}
});
```
## Samples
The following samples are provided to help you better understand the distributed data development:
- [`KvStore`: Distributed Database (eTS) (API8)](https://gitee.com/openharmony/app_samples/tree/master/data/Kvstore)
- [Distributed Database](https://gitee.com/openharmony/codelabs/tree/master/Data/JsDistributedData)
en/application-dev/database/database-relational-guidelines.md
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......@@ -34,7 +34,7 @@ The RDB provides APIs for inserting, deleting, updating, and querying data in th
| 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, 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.|
- **Updating data**
......@@ -190,7 +190,7 @@ You can obtain the distributed table name for a remote device based on the local
| -------- | -------- | -------- |
| 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.|
### Backing Up and Restore an RDB Store
### Backing Up and Restoring an RDB Store
**Backing Up an RDB Store**
......@@ -198,8 +198,8 @@ You can obtain the distributed table name for a remote device based on the local
| Class| API| Description|
| -------- | -------- | -------- |
| RdbStore |backup(destName:string, callback: AsyncCallback&lt;void&gt;):void| Backs up the RDB store with the specified name. 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 the RDB store with the specified name. This API uses a promise to return the result.<br>- **destName**: name of the RDB backup file.|
| 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.|
**Restoring an RDB Store**
......@@ -207,8 +207,8 @@ You can obtain the distributed table name for a remote device based on the local
| Class| API| Description|
| -------- | -------- | -------- |
| RdbStore |restore(srcName:string, callback: AsyncCallback&lt;void&gt;):void| Restores an RDB store using the specified 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 the specified backup file. This API uses a promise to return the result.<br>- **srcName**: name of the RDB backup file.|
| 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.|
## How to Develop
......@@ -270,7 +270,7 @@ 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.
......
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