Question

下面是我的数据

WH_QTY是可用的总数量，优先权是VIP，A，B，C。例如，应先将产品分配给VIP FIRST，然后再分配给A，B，C。

通过使用case语句，我已经能够获得VIP_Avail，A_Avail的正确值，但是转到B_Avail我收到以下错误。 “案例表达式只能嵌套到10级”

我要寻找的只是将VIP_Avail计算列用作我的A_Avail计算的基础，依此类推。但是，由于我要引用整个案例陈述，因此该陈述不成立。

以下是VIP_Avail的查询

IIF(ORDER_ITEMS.WH_OH =0,0,IIF(ORDER_ITEMS.WH_OH>=ORDER_AVAILABLE.VIP,ORDER_AVAILABLE.VIP,IIF(ORDER_ITEMS.WH_OH<ORDER_AVAILABLE.VIP,ORDER_ITEMS.WH_OH,0))) AS VIP_AVAIL

以下是对A_Avail的查询

CASE
WHEN
ORDER_ITEMS.WH_OH = 0 THEN 0


-- WHEN (WH_QTY-VIP)<A AND WH> 0 THEN (WH-VIP)
WHEN
((ORDER_ITEMS.WH_OH-IIF(ORDER_ITEMS.WH_OH =0,0,IIF(ORDER_ITEMS.WH_OH>=ORDER_AVAILABLE.VIP,ORDER_AVAILABLE.VIP,IIF(ORDER_ITEMS.WH_OH<ORDER_AVAILABLE.VIP,ORDER_ITEMS.WH_OH,0))))<A AND ORDER_ITEMS.WH_OH>0) THEN (ORDER_ITEMS.WH_OH-IIF(ORDER_ITEMS.WH_OH =0,0,IIF(ORDER_ITEMS.WH_OH>=ORDER_AVAILABLE.VIP,ORDER_AVAILABLE.VIP,IIF(ORDER_ITEMS.WH_OH<ORDER_AVAILABLE.VIP,ORDER_ITEMS.WH_OH,0))))
-- WHEN (WH_QTY - VIP) >= A THEN A
WHEN
(ORDER_ITEMS.WH_OH-IIF(ORDER_ITEMS.WH_OH =0,0,IIF(ORDER_ITEMS.WH_OH>=ORDER_AVAILABLE.VIP,ORDER_AVAILABLE.VIP,IIF(ORDER_ITEMS.WH_OH<ORDER_AVAILABLE.VIP,ORDER_ITEMS.WH_OH,0))))>=ORDER_AVAILABLE.A THEN ORDER_AVAILABLE.A
END AS A_AVAIL

谢谢，陈

Answer 1

假设您要更新表，我将执行以下操作：

UPDATE tickets_available
SET VIP_AVAIL = IIF(WH_OH > VIP, VIP, WH_OH),
    A_AVAIL = IIF(WH_OH - VIP > A, A , if (WH_OH - VIP >= 0, WH_OH - VIP, 0)),
    B_AVAIL = IIF(WH_OH - VIP - A > B, B, if (WH_OH - VIP - A >= 0, WH_OH - VIP - A, 0)),
    C_AVAIL = IIF(WH_OH - VIP - A - B > C, C, if (WH_OH - VIP - A - B >= 0, WH_OH - VIP - A - B, 0))

UPDATE tickets_available
SET VIP_AVAIL = CASE WHEN WH_OH > VIP THEN VIP ELSE WH_OH END,
    A_AVAIL = CASE WHEN WH_OH - VIP > A THEN A ELSE 
        CASE WHEN WH_OH - VIP >= 0 THEN WH_OH - VIP ELSE 0 END 
    END,
    B_AVAIL = CASE WHEN WH_OH - VIP - A > B THEN B ELSE
        CASE WHEN WH_OH - VIP - A >= 0 THEN  WH_OH - VIP - A ELSE 0 END 
    END,
    C_AVAIL = CASE WHEN WH_OH - VIP - A - B > C THEN C ELSE
        CASE WHEN WH_OH - VIP - A - B >= 0 THEN WH_OH - VIP - A - B ELSE 0 END
    END

我同时使用了IIF和CASE，因此您可以选择要使用的那个。最好您当然使用IIF，因为它更易读。

编辑：根据要求添加选择。

SELECT
    Item,
    WH_OH,
    VIP,
    IIF(WH_OH > VIP, VIP, WH_OH) AS VIP_AVAILABLE,
    A,
    IIF(WH_OH - VIP > A, A , if (WH_OH - VIP >= 0, WH_OH - VIP, 0)) AS A_AVAILABLE,
    B,
    IIF(WH_OH - VIP - A > B, B, if (WH_OH - VIP - A >= 0, WH_OH - VIP - A, 0)) AS B_AVAILABLE,
    C,
    IIF(WH_OH - VIP - A - B > C, C, if (WH_OH - VIP - A - B >= 0, WH_OH - VIP - A - B, 0)) AS C_AVAIL
FROM tickets_available

SQL Server通过避免“情况表达式只能嵌套到级别10”来使用IIF计算列

1 个答案: