diff --git a/docs/database/mysql/mysql-index.md b/docs/database/mysql/mysql-index.md
index 1c4b2ad2..d8a79132 100644
--- a/docs/database/mysql/mysql-index.md
+++ b/docs/database/mysql/mysql-index.md
@@ -187,6 +187,7 @@ SELECT id FROM table WHERE id=1;
 > 那么直接根据这个索引就可以查到数据，也无需回表。
 
 覆盖索引:
+
 ![](https://img-blog.csdnimg.cn/20210420165341868.png)
 
 ## 联合索引