diff --git a/zh-cn/application-dev/database/database-relational-guidelines.md b/zh-cn/application-dev/database/database-relational-guidelines.md
index 33f0665ceb21aa96f41307411a938755daf0686b..7899ba0076d8142210a045e7e0d0da1a6837d0e9 100644
--- a/zh-cn/application-dev/database/database-relational-guidelines.md
+++ b/zh-cn/application-dev/database/database-relational-guidelines.md
@@ -349,7 +349,7 @@
     ```js
     function storeObserver(devices) {
         for (let i = 0; i < devices.length; i++) {
-            console.log('device=' + device[i] + ' data changed')
+            console.log('device=' + device[i] + 'data changed')
         }
     }
     try {