如何根据条件按结果集从组中获取数据？

Question

I am getting the data between 2 dates group by year and month. Now for debugging purpose, I want to fetch check data from group result for a particular month but I am not getting how to do that.

Query:

SELECT CAST(MONTH(ActiveDate) AS VARCHAR(2)) + '-' + CAST(YEAR(ActiveDate) AS VARCHAR(4)) AS MyDate, 
    Count(*) AS Stats 
FROM JobListings
where CompanyID = 100
and Status = 'Active'
and (ActiveDate >= '9/1/2020' 
and ActiveDate <= '2/28/2021')
GROUP BY CAST(MONTH(ActiveDate) AS VARCHAR(2)) + '-' + CAST(YEAR(ActiveDate) AS VARCHAR(4))

This gives me the result like below:

MyDate       Stats
10-2020      3
11-2020      15
12 - 2020    4
and so on.

Now what I want is get the actual 3 records for "10-2020", so how do I inject a parent query to get the actual data from the group result set for particular month and year?

Answer 1

by this query, this should return only 3 records:

SELECT *
FROM JobListings
where 
    CompanyID = 100
    and Status = 'Active'
    and ActiveDate >= '10/01/2020' 
    and ActiveDate <= '11/01/2020'

well I add here instead of comments, try this and see what it returns:

select * 
, CAST(MONTH(ActiveDate) AS VARCHAR(2)) + '-' + CAST(YEAR(ActiveDate) AS VARCHAR(4)) Mydate
from JobListings
where CAST(MONTH(ActiveDate) AS VARCHAR(2)) + '-' + CAST(YEAR(ActiveDate) AS VARCHAR(4)) = '10-2020'

Answer 2

You need a window aggregate here, and no GROUP BY .

Also, I advise you to use EOMONTH instead of splitting the date and casting like you have.

SELECT
    EOMONTH(ActiveDate),
    Count(*) OVER (PARTITION BY EOMONTH(ActiveDate) AS Stats,
    *
FROM JobListings
where 
    CompanyID = 100
    and Status = 'Active'
    and (ActiveDate >= '9/1/2020' 
    and ActiveDate <= '2/28/2021')