數和組通過獲得總計

Question

SELECT 
    *, COUNT(examID) AS ExamCount 
FROM 
    ExamSession 
GROUP BY 
    [examID], [userID], [sessionID] 

這給了我一個結果集，但ExamCount有一個「1」，即使考試顯示在1個多行的每一行中...我想獲取examID在結果集中出現的次數。

所以結果集是這樣的：

examID | userID | sessionID | ExamCount 
--------------------------------------------------------- 
1111 | xxxxxx | xxxxxx | 1 
1111 | xxxxxx | xxxxxx | 1 
1111 | xxxxxx | xxxxxx | 1 
2222 | xxxxxx | xxxxxx | 1 
2222 | xxxxxx | xxxxxx | 1 
3333 | xxxxxx | xxxxxx | 1 
3333 | xxxxxx | xxxxxx | 1 
3333 | xxxxxx | xxxxxx | 1 
3333 | xxxxxx | xxxxxx | 1 

我怎樣才能獲得的倍examID出現次數的計數？

謝謝！

Answer 1

代碼：

COUNT(examID) OVER(PARTITION BY examID) AS ExamCount 

Answer 2

SELECT examId, COUNT(examID) AS ExamCount 
    FROM ExamSession 
    GROUP BY [examID] 

編輯： 如果你需要的所有列

select t1.*, t2.ExamCount 
from(
    SELECT *  
    FROM 
     ExamSession 
    GROUP BY 
     [examID], [userID], [sessionID]) t1 
inner join (
    SELECT examId, COUNT(examID) AS ExamCount 
     FROM ExamSession 
     GROUP BY [examID]) t2 
on t1.examID=t2.examID 

Answer 3

編輯：

select A.examid, B.UserId, b.SessionID, A.ExamCount from 
(SELECT examId, COUNT(examID) AS ExamCount 
    FROM ExamSession 
    GROUP BY [examID]) A 
JOIN (select [examID] ,[userID] ,[sessionID] from ExamSession) B 
on a.examid = b.examid 

Answer 4

爲了詳細說明jbarker答一點WER

if object_id(N'dbo.groupTry',N'U') is not null 
    drop table dbo.groupTry 
create table dbo.groupTry 
(
    examID int, 
    userID int, 
    sessionID int, 
    ExamCount int 
) 

insert into dbo.groupTry values 
(1111, 1234, 4321, 1), 
(1111, 9876, 6789, 1), 
(1111, 8765, 5678, 1), 
(2222, 7654, 4567, 1), 
(2222, 6543, 3456, 1), 
(3333, 5432, 2345, 1), 
(3333, 1987, 1789, 1), 
(3333, 1876, 1678, 1), 
(3333, 1765, 1567, 1) 

select 
    count(g.examID) over(partition by examID) as ExamCount, 
    g.examID, 
    g.userID, 
    g.sessionID, 
    g.ExamCount 
from dbo.groupTry g 
group by examID, 
    userID, 
    sessionID, 
    ExamCount 

在我自己簡單的話，經過短短的意思是：不看的所有列時，你算，只是看和計數examID的唯一行（因爲我們是由examID分區）。