得到错误＃1242，而从表

Question

我试图从表中删除数据和我的查询删除数据如下：

delete from mybadge where uid=5 and badge_name=(select concat(tag_name,'-Beginner') from tag,post_tags where post_tags.tag_id=tag.tag_id); 

我得到5个记录SELECT语句，我想删除所有那5条记录。

Answer 1

使用 - '在'关键字，而不是'='签署

delete from mybadge where uid=5 and badge_name in (select concat(tag_name,'-Beginner') from tag,post_tags where post_tags.tag_id=tag.tag_id); 

Answer 2

你的子查询，如你所说，返回5行。 但是，badge_name在同一行中不能有5个不同的值。这是一个有点像说：

delete from mybadge where uid=5 and badge_name=(5 different values) 

尝试

delete from mybadge where uid=5 and badge_name in (select concat(tag_name,'-Beginner') from tag,post_tags where post_tags.tag_id=tag.tag_id); 

Answer 3

如果select语句工作正常给你那么就删除所有的UID通过选择返回：

DELETE FROM mybadge WHERE uid IN(
SELECT uid 
FROM mybadge 
WHERE uid=5 
AND badge_name=(SELECT concat(tag_name,'-Beginner') 
       FROM tag,post_tags 
       WHERE post_tags.tag_id=tag.tag_id) 
);