SQL 在 where 子句上使用別名的服務器內部連接子查詢

Question

當被要求這樣做時，我認為這會很容易，但它一直在困擾着我。 我想使用先前連接的值應用於后續連接子查詢的 where 子句。 現在我已經硬編碼了一個值，但顯然不能保持這樣。 到目前為止，這是我所擁有的；

select
       SU.SUName
     , Q.[Name] AS [QualName]
     , DSP.EmployeeID AS [EmployeeID]
     , E.FirstName + ' ' + E.LastName AS [FullName]
  from SchedulingUnit            AS SU
 inner join StaffingProfile      AS SP  on SU.UnitID = SP.UnitID
 inner join DailyStaffingProfile AS DSP on SP.ID = DSP.ID
 inner join (SELECT QualID, [Name] FROM Qualifications WHERE QualID = **56**
              UNION
             SELECT BaseQualificationID, [Name]
               from QualificationDependencies AS QD
              inner join Qualifications AS Q ON Q.QualID = QD.QualifiesForID
              WHERE QualifiesForID IN (SELECT QualID FROM Qualifications WHERE QualID = **56** )) 
                                  AS Q ON SP.QualID = Q.QualID
 inner join Employee             AS E   on DSP.EmployeeID = E.EmpID
 where (@UnitID IS NULL OR SU.UnitID = @UnitID)
   and SU.HideInList = 0
   and NOT EXISTS (select * from EQ where EmpID = E.EmpID and SP.QualID = EQ.QualID)

我想用 SP.QualID 替換 56 的 2 個實例...這可能嗎？

Answer 1

您不需要將SP.QualID放在子查詢中。 子查詢后的SP.QualID = Q.QualID已經做了你想要的。 只需刪除子查詢中的兩個WHERE QualID = 56 。