Question

我正在尝试将以下查询更改为删除返回行的查询。

SELECT bad_rows.*
FROM votes as bad_rows
INNER JOIN(
    SELECT  MIN(id) as min_id, votes.object_id, votes.user_id 
FROM votes WHERE is_archived=FALSE AND 
     votes.direction < 20 
GROUP BY votes.object_id, votes.user_id, votes.content_type_id
having COUNT(votes.object_id) > 1
) AS double_rows ON 
    double_rows.object_id = bad_rows.object_id 
    AND double_rows.user_id=bad_rows.user_id 
    AND bad_rows.is_archived=False
    AND double_rows.min_id <> bad_rows.id

此选择有效，并为我提供了我想要删除的行。现在，如果我将select更改为删除，则我的查询不起作用。

DELETE bad_rows.*
FROM votes as bad_rows
INNER JOIN(
    SELECT  MIN(id) as min_id, votes.object_id, votes.user_id 
FROM votes WHERE is_archived=FALSE AND 
     votes.direction < 20 
GROUP BY votes.object_id, votes.user_id, votes.content_type_id
having COUNT(votes.object_id) > 1
) AS double_rows ON 
    double_rows.object_id = bad_rows.object_id 
    AND double_rows.user_id=bad_rows.user_id 
    AND bad_rows.is_archived=False
    AND double_rows.min_id <> bad_rows.id

错误：“bad_rows”或附近的语法错误第1行：删除bad_rows。*

Answer 1

您无法指定要删除的列（*中的bad_rows.*。）

此外，大多数数据库不允许您指定要删除的别名。因此，通常的删除方法如下：

DELETE  VOTES
WHERE   ID IN
        (
        <subquery selecting the ID's of the rows you want to delete>
        )

Answer 2

使用Andomar的建议我得到了它。

DELETE FROM votes WHERE id IN (
SELECT bad_rows.id
FROM votes as bad_rows
INNER JOIN(
SELECT  MIN(id) as min_id, votes.object_id, votes.user_id 
FROM votes where is_archived=FALSE and votes.direction < 20 

GROUP BY votes.object_id, votes.user_id, votes.content_type_id
having COUNT(votes.object_id) > 1
) as double_rows on double_rows.object_id = bad_rows.object_id and double_rows.user_id=bad_rows.user_id and bad_rows.is_archived=False
    and double_rows.min_id <> bad_rows.id
)

postgreSQL选择有效，但删除没有

2 个答案: