Question

我有一个SQL查询：

Select Top 3 dbo.FN_GetLRExpenseAmount(VendorBillID,LRNo,PM.PickupRunsheetNo)
From PickupRunsheetMaster PM Left Outer Join
     PickupRunsheetDetail PRD
     ON PM.PickupRunsheetNo = PRD.PickupRunsheetNo
Where ISNULL(VendorBillID,0) > 0

输出：

601.90
14.56
145.62

当我将函数dbo.FN_GetLRExpenseAmount(VendorBillID,LRNo,PM.PickupRunsheetNo)的返回值加到查询下面时，它就不会返回任何值

Select Top 3 SUM(dbo.FN_GetLRExpenseAmount(VendorBillID, LRNo, PM.PickupRunsheetNo))
From PickupRunsheetMaster PM Left Outer Join
     PickupRunsheetDetail PRD
     ON PM.PickupRunsheetNo = PRD.PickupRunsheetNo
Where ISNULL(VendorBillID,0) > 0

Answer 1

查询不一样。 TOP 3在第二个查询中不执行任何操作，因为它是一个只返回一行的聚合查询。

对于等效查询，请使用子查询或CTE：

select sum(val) as sum_3
from (Select Top 3 dbo.FN_GetLRExpenseAmount(VendorBillID, LRNo, PM.PickupRunsheetNo) as val
      From PickupRunsheetMaster PM Left Outer Join
           PickupRunsheetDetail PRD
           ON PM.PickupRunsheetNo = PRD.PickupRunsheetNo
      Where ISNULL(VendorBillID,0) > 0
     ) x

Answer 2

TOP 3 SUM为您提供此结果。要获取所需前3个记录的总和值，请创建子查询：

SELECT
     SUM(A.Expense)
FROM
(
    Select Top 3 dbo.FN_GetLRExpenseAmount(VendorBillID, LRNo, PM.PickupRunsheetNo) AS [Expense]
    From PickupRunsheetMaster PM Left Outer Join
         PickupRunsheetDetail PRD
         ON PM.PickupRunsheetNo = PRD.PickupRunsheetNo
    Where ISNULL(VendorBillID,0) > 0
) AS A

SQL函数返回值的总和

2 个答案: