得到錯誤＃1242，而從表

Question

我試圖從表中刪除數據和我的查詢刪除數據如下：

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個記錄SELECT語句，我想刪除所有那5條記錄。

Answer 1

使用 - '在'關鍵字，而不是'='簽署

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

你的子查詢，如你所說，返回5行。 但是，badge_name在同一行中不能有5個不同的值。這是一個有點像說：

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

嘗試

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語句工作正常給你那麼就刪除所有的UID通過選擇返回：

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) 
);