!2549 database示例代码低错检查问题修改

Merge pull request !2549 from 葛亚芳/master

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

@@ -97,7 +97,7 @@
    以下为监听对象数据变更的代码示例。
    
    ```js
-   changeCallback : function (sessionId, changeData) {
+   function changeCallback(sessionId, changeData) {
         console.info("change" + sessionId);
    
         if (changeData != null && changeData != undefined) {
@@ -147,7 +147,7 @@
 8. 监听分布式对象的上下线。可以监听对端分布式数据对象的上下线。
    以下为访问对象的代码示例：
    ```js
-    statusCallback : function (sessionId, networkid, status) {
+    function statusCallback(sessionId, networkid, status) {
       this.response += "status changed " + sessionId + " " + status + " " + networkId;
     }
    

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

@@ -248,7 +248,7 @@
    promise.then(() => {
        console.info("setDistributedTables success.")
    }).catch((err) => {
-       console.info("setDistributedTables failed."")
+       console.info("setDistributedTables failed.")
    })
    ```
 
@@ -263,7 +263,7 @@
     let predicate = new data_rdb.RdbPredicates('test')
     predicate.inDevices(['12345678abcde'])
     let promise = rdbStore.sync(rdb.SyncMode.SYNC_MODE_PUSH, predicate)
-    promise.then(result) {
+    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])