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sql 过滤重复记录和查询重复记录

WBOY
WBOYOriginal
2016-06-07 17:48:441566browse

分享二条sql语句,这两条就是我们经常碰到的一个是过滤所有重复记录,一个是获取重复记录的数据的方法,有需要的参考一下。

--查询一个表中有效去掉重复的记录,UserID为自增长主键,RoleID为重复字段

 代码如下 复制代码

SELECT MIN(UserID) AS UserID, RoleID FROM tmpTable GROUP BY RoleID

SELECT RoleID FROM tmpTable GROUP BY RoleID HAVING (COUNT(*) > 1) 获取重复记录

SELECT DISTINCT * FROM tmpTable 过滤重复记录

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