SQL总和或基于列减去（事务类型）

Question

我目前正在尝试获取SQL表中给定安全性的总交付量。我想计算每一行，如果它们是正交易类型（+）[txn类型]则将它们加起来，或者如果交易类型为负数（ - ），则从其余结果中删除该总额。我现在可以使用以下代码返回所有行的总和

SELECT     [STOCK REC NO], 
SUM(ISNULL([QTY DELIVERED], 0) + ISNULL([QTY DUE IN], 0) - ISNULL([QTY DUE OUT], 0)) AS [TOTAL QUANTITY]
FROM         bla_bla
WHERE     ([EVENT DATE] < '09/26/2012')
GROUP BY [STOCK REC NO]

TXN TYPE    QTY DELIVERED   QTY DUE IN  QTY DUE OUT EVENT DATE
+             1                                      28/11/2005
+             2                                      07/02/2006
-             3                                      22/11/2006
+             20                                     18/04/2011
+             40                                     19/04/2011

Answer 1

如果我正确地理解你的问题

SELECT     [STOCK REC NO], 
SUM(ISNULL(CASE WHEN [TXN TYPE] = '-' THEN -1 ELSE 1 END * [QTY DELIVERED], 0) +
    ISNULL(CASE WHEN [TXN TYPE] = '-' THEN -1 ELSE 1 END * [QTY DUE IN], 0) - 
    ISNULL(CASE WHEN [TXN TYPE] = '-' THEN -1 ELSE 1 END * [QTY DUE OUT], 0)) 
 AS [TOTAL QUANTITY]
FROM         bla_bla
WHERE     ([EVENT DATE] < '09/26/2012')
GROUP BY [STOCK REC NO]

Answer 2

SELECT  [STOCK REC NO],
        CASE TXN_TYPE
            WHEN '+' THEN SUM(ISNULL([QTY DELIVERED], 0) + ISNULL([QTY DUE IN], 0) + ISNULL([QTY DUE OUT], 0))
            ELSE SUM(ISNULL([QTY DELIVERED], 0) + ISNULL([QTY DUE IN], 0) - ISNULL([QTY DUE OUT], 0))
        END AS [TOTAL QUANTITY]
FROM    bla_bla
WHERE   ([EVENT DATE] < '09/26/2012')
GROUP BY
        [STOCK REC NO]

Answer 3

如果TXN_TYPE 总是 +或-，您可以尝试这个小技巧：

SELECT     [STOCK REC NO], 
           SUM(
             (TXN_TYPE + '1') * (
             ISNULL([QTY DELIVERED], 0) + ISNULL([QTY DUE IN], 0) - ISNULL([QTY DUE OUT], 0)
             )
           ) AS [TOTAL QUANTITY]
FROM         bla_bla
WHERE     ([EVENT DATE] < '09/26/2012')
GROUP BY [STOCK REC NO]

TXN_TYPE + '1'变为'+1'或'-1'。虽然它是一个字符串，但由于乘法，它会被隐式转换为数字。