SELECT語句別名上的無效對象名稱錯誤

Question

我編寫了一個SQL查詢，該查詢為兩個嵌套的SELECT語句中的每一個分配別名，並嘗試加入這些別名。

我的SQL查詢如下：

SELECT EmpID,
       (SELECT EmpID
              ,Count(*) * 8 AS [FullDayHours]
        FROM [database].[dbo].[tblLogTimes] 
        WHERE ActivityID = 43 
        AND WorkDate BETWEEN '2015-12-31 00:00:00.000' AND '2016-09-30 00:00:00.000'
        GROUP BY EmpID) AS [Rec1]
      ,(SELECT EmpID
              ,(Count(*) * 4) AS [HalfDayHours] 
        FROM [database].[dbo].[tblLogTimes] 
        WHERE ActivityID = 44 
        AND WorkDate BETWEEN '2015-12-31 00:00:00.000' AND '2016-09-30 00:00:00.000'
        GROUP BY EmpID) AS [Rec2]
FROM [database].[dbo].[tblLogTimes] E
INNER JOIN [Rec1] ON E.EmpID = [Rec1].EmpID
INNER JOIN [Rec2] ON E.EmpID = [Rec2].EmpID

嘗試執行查詢時，出現錯誤：無效的對象名稱'Rec1'。

我已經嘗試了查詢組件子語句的各種安排和配置，但無濟於事。

有見識，建議將非常受歡迎。 感謝您的光臨。

Answer 1

我相信這是您想要的，而不是將子查詢移至join ：

SELECT EmpID, FullDayHours, HalfDayHours
FROM [StaffSuite].[dbo].[tblLogTimes] E
INNER JOIN (SELECT EmpID
              ,Count(*) * 8 AS [FullDayHours]
        FROM [StaffSuite].[dbo].[tblLogTimes] 
        WHERE ActivityID = 43 
        AND WorkDate BETWEEN '2015-12-31 00:00:00.000' AND '2016-09-30 00:00:00.000'
        GROUP BY EmpID) AS [Rec1] ON E.EmpID = [Rec1].EmpID
INNER JOIN (SELECT EmpID
              ,(Count(*) * 4) AS [HalfDayHours] 
        FROM [StaffSuite].[dbo].[tblLogTimes] 
        WHERE ActivityID = 44 
        AND WorkDate BETWEEN '2015-12-31 00:00:00.000' AND '2016-09-30 00:00:00.000'
        GROUP BY EmpID) AS [Rec2] ON E.EmpID = [Rec2].EmpID

---

但是，您可以使用conditional aggregation來進一步簡化它：

SELECT EmpID, FullDayHours, HalfDayHours
FROM [StaffSuite].[dbo].[tblLogTimes] E
INNER JOIN (SELECT EmpID
              ,Count(case when activityid = 43 then 1 end) * 8 AS [FullDayHours]
              ,Count(case when activityid = 44 then 1 end) * 4 AS [HalfDayHours]
        FROM [StaffSuite].[dbo].[tblLogTimes] 
        WHERE ActivityID IN (43,44)
        AND WorkDate BETWEEN '2015-12-31 00:00:00.000' AND '2016-09-30 00:00:00.000'
        GROUP BY EmpID) AS [Rec1] ON E.EmpID = [Rec1].EmpID