如何编写实现Excel SUMIFS功能的SQL查询

Question

我有这样一张桌子：

Date        Sales   Department Store
02/01/2012   4.09    Toys       A
03/01/2012   5.90    Toys       A
02/01/2012   6.64    Toys       B
03/01/2012   4.71    Toys       B
02/01/2012   16.72   Toys       C
03/01/2012   1.37    Toys       C
02/01/2012   13.22   Movies     A
03/01/2012   18.06   Movies     A
02/01/2012   5.97    Movies     B
03/01/2012   16.71   Movies     B
02/01/2012   15.38   Movies     C
03/01/2012   19.75   Movies     C

并且想要一个这样的表，其中只考虑商店A和B：

Date        Toys    Movies
02/01/2012   10.73   19.19 
03/01/2012   10.61   34.77 

这里我们将在EXCEL中使用SUMIFS函数：

=SUMIFS(Value;Date;$H4;Department;I$3;Store;"<>C")

我们可以在SQL中编写什么？

考虑到这是一个简短的例子，数据库表有超过30个部门和更多的日期。我在使用脚本

SELECT DISTINCT Date,
ISNULL(MAX(CASE WHEN Department = 'Toys'  AND Store = 'A' THEN Sales END),0) +
ISNULL(MAX(CASE WHEN Department = 'Toys'  AND Store = 'B' THEN Sales END),0) [Toys],
ISNULL(MAX(CASE WHEN Department = 'Movies'  AND Store = 'A' THEN Sales END),0) +
ISNULL(MAX(CASE WHEN Department = 'Movies'  AND Store = 'B' THEN Sales END),0) [Movies]
FROM Table$
GROUP BY Date
ORDER BY Date

......但效率不高。谢谢你的任何提示。

Answer 1

您的查询没问题，但可以稍微改进一下：

SELEC Date,
      MAX(CASE WHEN Department = 'Toys' THEN Sales else 0 END) as [Toys],
      MAX(CASE WHEN Department = 'Movies' THEN Sales else 0 END) as [Movies]
FROM Table$
WHERE store in ('A', 'B')
GROUP BY Date
ORDER BY Date;

这将删除distinct，这是group by不必要的。它将store上的条件移动到where子句，因为它适用于所有行。并且，它通过在ISNULL()声明中包含else 0来删除case - 因此在该部门没有销售的商店将返回0而不是NULL。