Mysql删除重复数据保留最小的id_懂视

Mysql删除重复数据保留最小的id

2020-11-09 08:46:07 责编:小采

在网上查找删除重复数据保留id最小的数据，方法如下：

DELETE
FROM
 people
WHERE
 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
)

自己使用的时候显示报错：

1 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

暂时不知道是什么原因导致的。

然后想办法分布操作，首先筛选出有重复user的数据，然后用max()选出其中较大的那一行：

SELECT max(id) from tb GROUP BY user HAVING count(user)>1

然后再根据得到的max(id)逐条删除多余的数据

1 delete from tb where id=xx

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