!3499 Update Docs

Merge pull request !3499 from 吴冯山/OpenHarmony-3.1-Release

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

@@ -75,7 +75,7 @@ OpenHarmony系统中的分布式数据服务模块为开发者提供下面几种
            backup : false,
            autoSync : false,
            kvStoreType : distributedData.KVStoreType.SINGLE_VERSION,
-           securityLevel : distributedData.SecurityLevel.S2,
+           securityLevel : distributedData.SecurityLevel.S0,
        };
        kvManager.getKVStore('storeId', options, function (err, store) {
            if (err) {
@@ -159,18 +159,21 @@ OpenHarmony系统中的分布式数据服务模块为开发者提供下面几种
    deviceManager.createDeviceManager("bundleName", (err, value) => {
        if (!err) {
            devManager = value;
+           // get deviceIds
+           let deviceIds = [];
+           if (devManager != null) {
+               var devices = devManager.getTrustedDeviceListSync();
+               for (var i = 0; i < devices.length; i++) {
+                   deviceIds[i] = devices[i].deviceId;
+               }
+           }
+           try{
+               kvStore.sync(deviceIds, distributedData.SyncMode.PUSH_ONLY, 1000);
+           }catch (e) {
+                console.log("An unexpected error occurred. Error:" + e);
+           }
        }
    });
-   
-   // get deviceIds
-   let deviceIds = [];
-   if (devManager != null) {
-       var deviceList = devManager.getTrustedDeviceListSync();
-       for (var i = 0; i < deviceList.length; i++) {
-           deviceIds[i] = deviceList[i].deviceId;
-       }
-   }
-   kvStore.sync(deviceIds, distributedData.SyncMode.PUSH_ONLY, 1000);
    ```
 ## 相关实例
 针对分布式数据开发，有以下相关实例可供参考：