Question

我有一个名为etablissement_amenities的表

id
etablissement_id
amenities_id

我需要删除我的重复行。例如，我有这样的重复行。

id         etablissement_id          amenities_id
1          1                          1
2          1                          1
3          2                          2
4          6                          3
5          6                          3

我复制了我的桌子，我已经尝试了这个请求

DELETE FROM doublon 
WHERE id < ANY (SELECT etablissement_amenities.id 
                FROM doublon, etablissement_amenities 
                WHERE doublon.id = etablissement_amenities.id 
                AND doublon.amenities_id = etablissement_amenities.amenities_id 
                AND doublon.etablissement_id = etablissement_amenities.etablissement_id);

但我有错误

You can't specify target table 'doublon' for update in FROM clause

任何人都可以帮助我？

谢谢你。

Answer 1

此查询将希望从doublon

中删除所有重复的行

DELETE FROM doublon  WHERE id in 
( Select id  from `doublon` where `id` not in
    ( Select id
         From `doublon` 
         group  by etablissement_id,amenities_id
         having Count(etablissement_id) > 1  and Count(amenities_id) > 1
         union
      Select id
         From `doublon` 
         group  by etablissement_id,amenities_id
         having Count(etablissement_id) = 1  and Count(amenities_id) = 1
     )
 )

以下是重复记录 sqlfiddle

Answer 2

您不能在MySQL的delete或update中再次使用同一个表。相反，只需使用join：

DELETE ea
    FROM etablissement_amenities ea JOIN
         (select ea.etablissement_id, MIN(ea.id) as minid
          from etablissement_amenities ea
          group by ea.etablissement_id
         ) ead
         on ea.etablissement_id = ead.etablissement_id and
            ea.id > ead.minid;

我不知道doublon是什么。您的问题陈述只提到一个表etablissement_amenities。

Answer 3

在上述查询中没有关于表doublelon的信息。

要删除或更新引用相同表的子查询的表，请尝试将子查询括在临时派生表中，如下所示。

DELETE FROM doublon 
WHERE   id < ANY (Select * from (SELECT etablissement_amenities.id 
                FROM doublon, etablissement_amenities 
                WHERE doublon.id = etablissement_amenities.id 
                AND doublon.amenities_id = etablissement_amenities.amenities_id 
                AND doublon.etablissement_id = etablissement_amenities.etablissement_id) as Tmp);

P.s. The answer is to fix the error in above query. It is not about deleting duplicate values.....

删除表上的重复行

3 个答案: