SQL Count case，我有一个唯一的字段

如何解决SQL Count case，我有一个唯一的字段

一直在使用下面的代码来计算所有商店每天发生的次数。只是简单地计算 Site_Review_Date。

所以 1 家商店可能有 2 次或更多次出现

现在我每天都需要独特的商店事件。不断被难住，所以请寻求帮助。

数据示例

Store   Site_Review_Date
90      2021-03-02
90      2021-03-02
1       2021-03-02
3       2021-03-02
20      2021-03-02
87      2021-03-02

所以对于星期二，如果我计算日期，我会寻找 5 而不是 6

Declare  @reportStartDate date

set @reportStartDate ='2021-1-03'


SELECT 
     
    DATEPART(wk,@reportStartDate ) as Week,COUNT(CASE WHEN DATEDIFF(dd,@reportStartDate,Site_Review_Date) = 0 THEN 1 END) AS S,Site_Review_Date) = 1 THEN 1 END) AS M,Site_Review_Date) = 2 THEN 1 END) AS T,Site_Review_Date) = 3 THEN 1 END) AS W,Site_Review_Date) = 4 THEN 1 END) AS R,Site_Review_Date) = 5 THEN 1 END) AS F,Site_Review_Date) = 6 THEN 1 END) AS Sat,COUNT(*) AS TOTAL
FROM dbo.Map_Survey_Tracking

WHERE Site_Review_Date BETWEEN @reportStartDate/*Sunday,report start date*/ AND DATEADD(dd,7,@reportStartDate)  

结果

Week    S   M   T   W   R   F   Sat TOTAL
2   0   4   5   5   10  9   6   42

解决方法

我想你想要count(distinct)：

SELECT DATEPART(wk,@reportStartDate ) as Week,COUNT(DISTINCT CASE WHEN DATEDIFF(dd,@reportStartDate,Site_Review_Date) = 0 THEN Store END) AS S,Site_Review_Date) = 1 THEN Store END) AS M,Site_Review_Date) = 2 THEN Store END) AS T,Site_Review_Date) = 3 THEN Store END) AS W,Site_Review_Date) = 4 THEN Store END) AS R,Site_Review_Date) = 5 THEN Store END) AS F,Site_Review_Date) = 6 THEN Store END) AS Sat,COUNT(*) AS TOTAL
FROM dbo.Map_Survey_Tracking    
WHERE Site_Review_Date BETWEEN @reportStartDate/*Sunday,report start date*/ AND DATEADD(dd,7,@reportStartDate)  ;

我注意到您使用 DATEDIFF() 表示星期几。 DATENAME() 或 DATEPART() 似乎更透明（尽管它们受全局设置的影响）。