dtoka218420 2014-01-17 16:14
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使用JOIN链接表

I have 3 tables; memberID, membership, person

I need firstname lastname from 'membership' and MemberID and PersonID from 'memberID' The following gives me a list of names.

   SELECT 
   CONCAT(P.FirstName, ' ', P.LastName) as FullName
   FROM `membership` M
   INNER JOIN `memberID` MI ON M.`MembershipID` = MI.`MembershipID`
   INNER JOIN `person` P ON MI.`PersonID` = P.`PersonID`
   AND P.`IsActive` =1

The following fails, how do I add the PersonID and MembershipID columns, . I believe I require another INNER JOIN but I don't know how to construct it.

   SELECT
   CONCAT(P.FirstName, ' ', P.LastName) as FullName
   FROM `membership` M
   MI.'membershipID' MI.'PersonID' FROM  'membershipID' MI
   INNER JOIN `memberID` MI ON M.`MembershipID` = MI.`MembershipID`

   INNER JOIN `person` P ON MI.`PersonID` = P.`PersonID`
   AND P.`IsActive` =1
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1条回答 默认 最新

  • dqhmtpuy94946 2014-01-17 16:18
    关注

    Presumably those columns are already in the tables being referenced:

    SELECT CONCAT(P.FirstName, ' ', P.LastName) as FullName,
           MI.PersonID, M.`MembershipID`
    FROM `membership` M INNER JOIN
         `memberID` MI
         ON M.`MembershipID` = MI.`MembershipID` INNER JOIN
         `person` P
         ON MI.`PersonID` = P.`PersonID` AND P.`IsActive` = 1;
    

    You don't need additional joins, just additional columns in the select.

    本回答被题主选为最佳回答 , 对您是否有帮助呢?
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