对两个单独的列使用distinct和case

Question

我使用以下代码按年计算案例：

COUNT(CASE WHEN Year(FilingDate)=2008 THEN 1 ELSE NULL END) AS '2008'

我希望只在另一列不同时计算这些情况。另一列被称为'FilingDate'我想象的会是这样的：

COUNT(CASE distinct (DocketNumber) WHEN Year(FilingDate)=2008 THEN 1 ELSE NULL END) AS '2008',

样本记录：

DocketNumber FilingDate

123 2008

123 2008

123 2008

111 2009

112 2009

我只想接受= 1 任何想法？

由于

Answer 1

使用SUBQUERY和GROUP BY子句

的选项

SELECT COUNT(CASE WHEN YearFilingDate = 2008 THEN 1 END) AS '2008'
FROM
 (      
  SELECT Year(FilingDate) AS YearFilingDate, DocketNumber
  FROM dbo.test55
  GROUP BY Year(FilingDate), DocketNumber
  ) x

SQLFiddle上的演示

Answer 2

SELECT COUNT(CASE WHEN Year(FilingDate)=2008 THEN 1 ELSE NULL END) AS '2008'
GROUP BY DocketNumber

可能是。