如何结合GROUP BY,ORDER BY和HAVING
技术问答
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2023-09-14
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如何正确结合这句话?
/ s6 r b9 V3 F/ C, _SELECT *,COUNT(*)FROM user_logGROUP BY EmailORDER BY UpdateDate DESCHAVING COUNT(*) > 1让我知道* O5 X( }. }9 C' h& G; s. z
! L* j }4 b7 ?, ~ 解决方案: 3 C; U4 _* Y# ~. D5 Z& j
ORDER BY 永远是最后…/ p& {, J- d& M7 }) J
但是,你需要选择你 实际上想要 字段,然后只选择那些字段并按它们分组。SELECT *并GROUP BY Email它将为您提供所有字段( K- c, M1 n5 L; T( a) }/ F
随机值 ,但Email。大多数RDBMS这个操作甚至不允许你执行,因为它创造了问题,但是MySQL是例外。% `+ I7 s; X0 p: W. A& }
SELECT Email,COUNT(*)FROM user_logGROUP BY EmailHAVING COUNT(*) > 1ORDER BY UpdateDate DESC |
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