update docs

Signed-off-by: NAnnie_wang <annie.wangli@huawei.com>

en/application-dev/database/database-distributedobject-guidelines.md

@@ -17,7 +17,7 @@ Call **createDistributedObject()** to create a distributed data object instance.
 
 **Table 1** API for creating a distributed data object instance
 
-| Bundle Name| API| Description|
+| Package | API| Description|
 | -------- | -------- | -------- |
 | ohos.data.distributedDataObject| createDistributedObject(source: object): DistributedObject | Creates a distributed data object instance for data operations.<br>- **source**: attributes of the distributed data object to create.<br>- **DistributedObject**: returns the distributed data object created.|
 
@@ -27,7 +27,7 @@ Call **genSessionId()** to generate a session ID randomly. The generated session
 
 **Table 2** API for generating a session ID randomly
 
-| Bundle Name| API| Description|
+| Package | API| Description|
 | -------- | -------- | -------- |
 | ohos.data.distributedDataObject| genSessionId(): string | Generates a session ID, which can be used as the session ID of a distributed data object.|
 
@@ -201,7 +201,7 @@ The following example shows how to implement distributed data object synchroniza
            });
        }
    } 
-   
+
    // To refresh the page in changeCallback, correctly bind (this) to the changeCallback.
    localObject.on("change", this.changeCallback.bind(this));
    ```

en/application-dev/database/database-preference-guidelines.md

@@ -113,22 +113,20 @@ You can use the following APIs to delete a **Preferences** instance or data file
 
    ```ts
    // Obtain the context.
-   import UIAbility from '@ohos.app.ability.UIAbility'
-   let context = null;
+   import UIAbility from '@ohos.app.ability.UIAbility';
    let preferences = null;
    export default class EntryAbility extends UIAbility {
-       onWindowStageCreate(windowStage){
-           context = this.context;
+       onWindowStageCreate(windowStage) {
+           let promise = data_preferences.getPreferences(this.context, 'mystore');
+            promise.then((pref) => {
+                preferences = pref;
+            }).catch((err) => {
+                console.info("Failed to get the preferences.");
+            })
        }
    }
    
-   let promise = data_preferences.getPreferences(context, 'mystore');
    
-   promise.then((pref) => {
-       preferences = pref;
-   }).catch((err) => {
-       console.info("Failed to get the preferences.");
-   })
    ```
 
 3. Write data.