mysql - 根据一个从 4 个表中删除行？

Question

我正在寻找一个查询来删除数据库中用户的所有记录。有一个表用户：

user_id | name

一张桌子帖子

post_id | user_id | post_html

一张表posts_tags

id | post_id | tag_id

一张表标签

id | user_id | tag

我正在寻找从这 4 个表中删除链接到用户的所有记录......喜欢

delete from tags t inner join posts_tags bt on t.id = bt.tag_id where ???

谢谢

Answer 1

如果你愿意，你可以在一个语句中做到这一点：

delete u, p, pt, t
    from users u join
         posts p
         on u.id = p.user_id join
         posts_tags pt 
         on p.id = pt.post_id join
         tags t
         on t.id = pt.tag_id
    where u.id = @YOURUSERID;

Answer 2

我同意 zerkms - 你可以使用级联外键。但它也可以写成 SQL 查询，但是如果你有外键，你必须按照正确的顺序来做，比如：

delete from posts_tags
where
    tag_id in (select id from tags where user_id = <your user id>) or
    post_id in (select post_id from posts where user_id = <your user id>)

delete from tags
where user_id = <your user id>

delete from posts
where user_id = <your user id>

delete from users
where user_id = <your user id>