sql去除重复记录 且保留id最小的 没用

第一步：查询重复记录

 

1.  
   SELECT * FROM TableName
2.  
   WHERE RepeatFiled IN (
3.  
   SELECT RepeatFiled
4.  
   FROM TableName
5.  
   GROUP BY RepeatFiled
6.  
   HAVING COUNT(RepeatFiled) > 1
7.  
   )

这一段逻辑很简单，就是把重复条数大于1的全部都搞出来就行了。

第二步：删除重复记录，只保留一条

 

1.  
   SELECT * FROM TableName
2.  
   WHERE RepeatFiled IN (
3.  
   SELECT RepeatFiled
4.  
   FROM TableName
5.  
   GROUP BY RepeatFiled
6.  
   HAVING COUNT(RepeatFiled) > 1
7.  
   AND
8.  
   ID NOT IN (
9.  
   SELECT MIN(ID)
10.  
    FROM TableName
11.  
    GROUP RepeatFiled
12.  
    HAVING COUNT(RepeatFiled) > 1
13.  
    )
14.  
    )

在上一步的基础上继续过滤，那就把最小值留下就行了，大功告成！