在網上查找刪除重復數據保留id最小的數據,方法如下:
DELETEFROM peopleWHERE peopleName IN ( SELECT peopleName FROM people GROUP BY peopleName HAVING count(peopleName) > 1 )AND peopleId NOT IN ( SELECT min(peopleId) FROM people GROUP BY peopleName HAVING count(peopleName) > 1)
自己使用的時候顯示報錯:
delete from tb where id in (SELECT max(id) from tb GROUP BY user HAVING count(user)>1)
[Err] 1093 - You can't specify target table ‘XXX' for update in FROM clause
暫時不知道是什么原因導致的。
然后想辦法分布操作,首先篩選出有重復user的數據,然后用max()選出其中較大的那一行:
SELECT max(id) from tb GROUP BY user HAVING count(user)>1
然后再根據得到的max(id)逐條刪除多余的數據
delete from tb where id=xx
是個笨方法,暫時先解決問題吧。
總結
以上所述是小編給大家介紹的Mysql刪除重復數據保留最小的id 的解決方法,希望對大家有所幫助,如果大家有任何疑問歡迎給我留言,小編會及時回復大家的!
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