Mysql刪除重復(fù)數(shù)據(jù)保留最小的id 的解決方法

在網(wǎng)上查找刪除重復(fù)數(shù)據(jù)保留id最小的數(shù)據(jù)，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
)

自己使用的時(shí)候顯示報(bào)錯(cuò)：

 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(shí)不知道是什么原因?qū)е碌摹?/p>

然后想辦法分布操作，首先篩選出有重復(fù)user的數(shù)據(jù)，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(jù)得到的max(id)逐條刪除多余的數(shù)據(jù)

delete from tb where id=xx

是個(gè)笨方法，暫時(shí)先解決問(wèn)題吧。

總結(jié)

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