如何组合GROUP BY,ORDER BY和HAVING

Question

如何正确组合此声明.

SELECT *, COUNT(*)
FROM user_log
GROUP BY Email
ORDER BY UpdateDate DESC
HAVING COUNT(*) > 1

让我知道

Answer 1

ORDER BY 总是最后......

但是,您需要选择您实际想要的字段,然后只选择它们并按它们分组. SELECT *并且GROUP BY Email会给你所有领域的随机价值Email.大多数RDBMS甚至不允许你这样做,因为它创建的问题,但MySQL是例外.

SELECT Email, COUNT(*)
FROM user_log
GROUP BY Email
HAVING COUNT(*) > 1
ORDER BY UpdateDate DESC