rdb开发指南同步FA模型获取context

Signed-off-by: Nltdong <donglongtao@huawei.com>

zh-cn/application-dev/database/database-relational-guidelines.md

@@ -197,16 +197,45 @@
    (3) 创建数据库。
 
    示例代码如下：
+   FA模型示例：
 
     ```js
+    
     import data_rdb from '@ohos.data.rdb'
-
-    const CREATE_TABLE_TEST = "CREATE TABLE IF NOT EXISTS test (" + "id INTEGER PRIMARY KEY AUTOINCREMENT, " + "name TEXT NOT NULL, " + "age INTEGER, " + "salary REAL, " + "blobType BLOB)";
-    const STORE_CONFIG = { name: "rdbstore.db" }
-    data_rdb.getRdbStore(this.context, STORE_CONFIG, 1, function (err, rdbStore) {
+    // 获取context
+   import featureAbility from '@ohos.ability.featureAbility'
+   var context = featureAbility.getContext()
+   
+   const CREATE_TABLE_TEST = "CREATE TABLE IF NOT EXISTS test (" + "id INTEGER PRIMARY KEY AUTOINCREMENT, " + "name TEXT NOT NULL, " + "age INTEGER, " + "salary REAL, " + "blobType BLOB)";
+   
+   const STORE_CONFIG = { name: "RdbTest.db" }
+   data_rdb.getRdbStore(context, STORE_CONFIG, 1, function (err, rdbStore) {
       rdbStore.executeSql(CREATE_TABLE_TEST)
       console.info('create table done.')
-    })
+   })
+    
+    ```
+    Stage模型示例：
+     ```js
+    
+    import data_rdb from '@ohos.data.rdb'
+    // 获取context
+   import Ability from '@ohos.application.Ability'
+   var context
+   class MainAbility extends Ability{
+         onWindowStageCreate(windowStage){
+             context = this.context
+       }
+   }
+   
+   const CREATE_TABLE_TEST = "CREATE TABLE IF NOT EXISTS test (" + "id INTEGER PRIMARY KEY AUTOINCREMENT, " + "name TEXT NOT NULL, " + "age INTEGER, " + "salary REAL, " + "blobType BLOB)";
+   
+   const STORE_CONFIG = { name: "rdbstore.db" }
+   data_rdb.getRdbStore(context, STORE_CONFIG, 1, function (err, rdbStore) {
+       rdbStore.executeSql(CREATE_TABLE_TEST)
+       console.info('create table done.')
+   })
+   
     ```
 
 2. 插入数据。
@@ -395,4 +424,4 @@
 ## 相关实例
 针对关系型数据库开发，有以下相关实例可供参考：
 - [`DistributedRdb`：分布式关系型数据库（eTS）（API8）（Full SDK）](https://gitee.com/openharmony/applications_app_samples/tree/master/data/DistributedRdb)
-- [关系型数据库（JS）（API8）](https://gitee.com/openharmony/codelabs/tree/master/Data/JSRelationshipData)
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+- [关系型数据库（JS）（API8）](https://gitee.com/openharmony/codelabs/tree/master/Data/JSRelationshipData)d
\ No newline at end of file