Question

您好我正在尝试复制我在MS Access中使用的复杂IIF函数，但似乎无法使用CASE将其转换为SLQ 2008。我正在尝试创建类似这样的WHERE子句

..... WHERE (IIF([Created Date]= NULL, IIF(DATEDIFF(day,[Created Date],[POSTED Date])<=3,1,IIF([Created Date] BETWEEN [Disti Reported Sales Date] AND [Posted Date]),1,NULL)))=1 AND ...... 基本上它的作用是从一列查看日期并将其与其他两列进行比较，但如果其中一列是NULL，则它使用不同的比较。

Answer 1

字面翻译应该看起来很接近：

WHERE (CASE
    WHEN [Created Date] IS NULL
    THEN (CASE
        WHEN DATEDIFF(DD, [Created Date], [POSTED Date]) <= 3 
        THEN 1
        ELSE (CASE
            WHEN [Created Date] BETWEEN [Disti Reported Sales Date] AND [Posted Date]
            THEN 1 
            ELSE 0
            END)
        END)
    ELSE 0
    END) = 1

但是，这可以简化为：

WHERE (CASE
    WHEN [Created Date] IS NULL AND DATEDIFF(DD, [Created Date], [POSTED Date]) <= 3 THEN 1
    WHEN [Created Date] IS NULL AND [Created Date] BETWEEN [Disti Reported Sales Date] AND [Posted Date] THEN 1
    ELSE 0 END) = 1

如我的评论中所述，如果[创建日期]为空，您仍尝试在任何计算中仍然使用它，这似乎仍然很奇怪。

复杂的IIF到SQL 2008

1 个答案: