如果變量爲空，則不會過濾的存儲過程

Question

我有我想用於SAP Crystal報表的此存儲過程。

SELECT 
    t0.DocNum AS ReceiptNo, t2.DocEntry AS InvoiceNo, 
    t0.DocDate, t1.CheckAct, 
    t1.CheckNum, t3.AcctName, 
    CASE 
     WHEN (t0.CardName IS NULL) THEN t0.Address 
            ELSE t0.CardName 
    END AS CustName, 
    CASE 
     WHEN ((t1.CheckNum IS NULL OR t1.CheckNum = 0) 
       AND t0.TrsfrRef IS NULL) THEN 'Cash' 
     WHEN (t1.CheckNum > 0 
       AND t0.TrsfrRef IS NULL) THEN 'Cheque' 
     ELSE 'Transfer' 
    END AS PayType, 
    CASE 
     WHEN (t1.CheckNum > 0 AND t0.TrsfrRef IS NULL) THEN t1.CheckSum 
     ELSE t0.DocTotal 
    END AS DocTotal 
FROM 
    ORCT t0 
LEFT OUTER JOIN 
    RCT1 t1 ON t1.docnum = t0.docnum 
LEFT OUTER JOIN 
    RCT2 t2 ON t0.DocEntry = t2.DocNum 
LEFT OUTER JOIN 
    OACT t3 ON t1.CheckAct = t3.AcctCode 
WHERE 
    t0.DocDate BETWEEN @BeginDate AND @EndDate 
    AND t0.Canceled = 'N' 
    AND t3.AcctCode = @Account 

在最後一行，我已經聲明的變量@Account可以過濾通過帳號的結果。我希望我的報告能夠工作，以便如果未選擇某個帳戶（空），則會返回所有帳戶結果。

我該如何做到這一點？

任何幫助表示讚賞。

Answer 1

添加到末尾

or t3.AcctCode is null 

Answer 2

這聽起來像你想被有效省略最後一句，如果@Account爲null。如果是，請嘗試以下操作：

... AND t0.Canceled = 'N' AND 
(@Account IS NULL OR t3.AcctCode = @Account) 

Answer 3

您可以使用IF ELSE

IF @Account IS NULL 
    BEGIN 
     --Your Query without "AND t3.AcctCode = @Account" 
    END 
ELSE 
    BEGIN 
     -- Your Query 
    END 

您也可以將您的最後一行更改爲：

AND (t3.AcctCode = @Account OR @Account IS NULL)