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

一个表格帖子

post_id | user_id | post_html

一个表posts_tags

id | post_id | tag_id

一个表标签

id | user_id | tag

我希望从这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

如果您愿意，可以在一个声明中完成：

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 - 您可以使用级联外键。但它也可以写成SQL查询，但如果你有外键，你必须按正确的顺序执行，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>

从一个表中删除4个表中的行？

2 个答案: