Question

我有3张桌子; memberID，会员，人

我需要来自'membership'的名字姓氏来自'memberID'的MemberID和PersonID 以下给出了一个名单。

   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

以下失败，如何添加PersonID和MembershipID列，。我相信我需要另一个INNER JOIN，但我不知道如何构建它。

   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

Answer 1

可能这些列已经在被引用的表中：

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;

您不需要其他联接，只需要select中的其他列。

使用JOIN链接表

1 个答案: