Question

我的数据库有以下表格，

User (id, name)
EmailTemplate (id, subject, template)
EmailTrack (id, user_id, email_template_id)

我想通过SQL查询吸引尚未发送特定email_template的用户。

Answer 1

您可以使用not exists运算符：

SELECT *
FROM   user u
WHERE  NOT EXISTS (SELECT *
                   FROM   emailtemplate temp
                   JOIN   emailtrack track ON temp.id = track.email_template_id
                   WHERE  template = 'some_specific_template' AND
                          track.user_id = u.id)

获取未发送电子邮件的用户MySQL

1 个答案: