Mysql删除重复数据保留最小的id
作者: default|标签:MYSQL 保留 数据|2017-10-13 10:11
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

以上就是Mysql删除重复数据保留最小的id的详细内容,更多请关注php中文网其它相关文章!

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