MySQL删除"非活动"行

Question

我有两张桌子:

用户

id | 名字| 邮件| 通过| 盐

项

id | uid | 标题| 文字| 时间戳

现在我要删除所有entries带有a的行uid,这在user-table中是不存在的(已删除的用户)

我认为这可能是这样的:

DELETE entries FROM user, entries WHERE [What comes here? I don't know :(]

Answer 1

DELETE FROM entries WHERE uid NOT IN (SELECT DISTINCT id FROM user);