Question

我有三个SELECT语句，每个语句都返回一个总数，'New Cases'，'Closes Cases'，'Existing Cases'。如何组合它们以便在一个结果集中返回它们。

即我需要一张带有3个字段的表格，“新案例”，“关闭案例”和“现有案例”各有一个

SELECT     COUNT(CaseID) AS 'New Cases'
FROM         dbo.ClientCase
WHERE     (CaseStartDate >= CONVERT(DATETIME, '2009-01-01 00:00:00', 102))
  AND     (CaseStartDate <= CONVERT(DATETIME, '2009-03-31 00:00:00', 102))

SELECT     COUNT(CaseID) AS 'Closed Cases'
FROM         dbo.ClientCase
WHERE     (CaseClosedDate >= CONVERT(DATETIME, '2009-01-01 00:00:00', 102))
  AND     (CaseClosedDate <= CONVERT(DATETIME, '2009-03-31 00:00:00', 102))

SELECT     COUNT(CaseID) AS 'Existing Cases'
FROM         dbo.ClientCase
WHERE     (CaseStartDate <= CONVERT(DATETIME, '2009-03-31 00:00:00', 102))

Answer 1

在计算相同数据时，您可以并行执行：

select
   sum(case when CaseStartDate between '2009-01-01' and '2009-03-31' then 1 else 0 end) as [New Cases],
   sum(case when CaseClosedDate between '2009-01-01' and '2009-03-31' then 1 else 0 end) as [Closed Cases],
   sum(case when CaseStartDate <= '2009-03-31' then 1 else 0 end) as [Existing Cases]
from
   dbo.ClientCase

Answer 2

@Mitch，@ Guffa ..一个很好的解决方案，但为了获得正确的结果，您需要考虑CaseStartDate和CaseClosedDate字段。例如。在New Cases中，如果你不过滤CaseClosedDate数据，你将得不到正确的no。 NewCases，因为它仍将在封闭的情况下计算。

抱歉，我必须将其作为答案发布，因为我没有enuf声誉来添加评论。

SQL组合几个SELECT结果

2 个答案: