对SQL Server中列的分组计数求和

Question

I have details of the count of users and the month in the 2nd column and the teams name in the 3rd columns as below. I want the o/p to give the sum of the users column for 7th, 8th and 9th month grouped wrt the month.

 Count_of_Users Month   Team
 ----------------------------
       1          7       a
       1          8       a
       1          9       a
       1          7       a
       1          8       a
       1          9       a
       1          7       a
       1          8       a
       1          9       a

Query:

SELECT  
    (COUNT(DISTINCT([username]))) AS A,
    MONTH([Date]) AS B,
    Team
FROM
    myTable
GROUP BY
    [UserName], MONTH([Date]), Team
ORDER BY 
    [UserName], MONTH([Date]), Team

This is the query i had for the above o/p. I am not sure if i should be using UNION ALL to proceed. Any inputs are appreciated.

Answer 1

I'm not sure what you want, but your current version doesn't seem very useful. Is this what you intend?

SELECT COUNT(DISTINCT [username]) AS A,
       MONTH([Date]) AS B,
       Team
FROM myTable
GROUP BY MONTH([Date]), Team
ORDER BY MONTH([Date]), Team