如何在一个SELECT查询中查看2个名称

问题描述 投票:2回答:2

我想通过将它们与我的[[cases表中的usrIDres_usrID字段进行匹配以从users表中使用 usrGivenName字段。我想在同一行上查看它们。我该怎么办?

SELECT caseID ,c.date_created ,c.date_approval_request ,c.date_closed ,u.usrGivenName ,c.muh_usrID FROM cases AS c JOIN users AS u ON c.usrID=u.usrID
sql
2个回答
2
投票
SELECT caseID ,c.date_created ,c.date_approval_request ,c.date_closed ,coalesce(u.usrGivenName, ru.usrGivenName, 'Not Available') ,c.muh_usrID FROM cases AS c left JOIN users AS u ON c.usrID = u.usrID left JOIN users AS ru ON c.res_usrID = ru.usrID
没有测试,但是您会明白的。

1
投票
仅使用self join(即,附加连接到同一表):

SELECT c.caseID , c.date_created , c.date_approval_request , c.date_closed , u1.usrGivenName as user_name , c.muh_usrID , u2.usrGivenName as res_user_name FROM cases AS c JOIN users AS u1 ON c.usrID = u.usrID JOIN users AS u2 ON c.res_usrID = u.usrID

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