SQL服務器：選擇一些東西作爲 '變量'

Question

我做SELECT的東西爲 '變量'，像這樣

SELECT 
    SUM(CASE WHEN BA_Idx = 503 THEN BIL_Debit ELSE 0 END) AS 'SUM_DEBIT_503', 
    SUM(CASE WHEN BA_Idx = 504 THEN BIL_Debit ELSE 0 END) AS 'SUM_DEBIT_504' 
FROM  
    Bill 
WHERE 
    (@MEM_Idx = 0 OR MEM_Idx = @MEM_Idx) AND 
    (LEFT(BIL_YYMMDD,7) = @BILM_YYMM) AND   
    BIL_IsValid = 'True' 

SELECT @BILFC_TotalLaborCost = SUM_DEBIT_503 + SUM_DEBIT_504 

我想辦法的變量（'SUM_DEBIT_503'， 'SUM_DEBIT_504'）計算@BILFC_TotalLaborCost 。

我該怎麼辦？

Answer 1

您可以在查詢中設置的變量。這樣，如果你需要它們，它們可以在以後使用。

DECLARE @SumDebit503 <SOMETYPE> 
DECLARE @SumDebit504 <SOMETYPE> 

SELECT @SumDebit503 = SUM(CASE WHEN BA_Idx = 503 THEN BIL_Debit ELSE 0 END), 
     @SumDebit504 = SUM(CASE WHEN BA_Idx = 504 THEN BIL_Debit ELSE 0 END) 
FROM Bill 
WHERE 
    (@MEM_Idx = 0 OR MEM_Idx = @MEM_Idx) 
    AND (LEFT(BIL_YYMMDD, 7) = @BILM_YYMM) 
    AND BIL_IsValid = 'True' 

SELECT @BILFC_TotalLaborCost = @SumDebit503 + @SumDebit504 

Answer 2

不要在SELECT本身的分配：

SELECT @BILFC_TotalLaborCost = 
    SUM(CASE WHEN BA_Idx = 503 THEN BIL_Debit ELSE 0 END) + 
    SUM(CASE WHEN BA_Idx = 504 THEN BIL_Debit ELSE 0 END) 
FROM Bill 
WHERE 
    (@MEM_Idx = 0 OR MEM_Idx = @MEM_Idx) 
    AND (LEFT(BIL_YYMMDD, 7) = @BILM_YYMM) 
    AND BIL_IsValid = 'True'