计算日期时间每个月内的行数，按年份月份分组

Question

I'm having trouble getting a sproc to give me this type of output:

+-----------+------------------+
|   Month   | NoOfModifcations |
+-----------+------------------+
| Jan  2008 |                5 |
| Nov  2008 |                6 |
| Feb  2010 |               20 |
| Jul  2013 |                7 |
+-----------+------------------+

So far i managed to get the output to look like this, but i haven't yet managed to get the output to be sorted by year, then month - it's going alphabetically. Here's what i have so far:

SELECT convert(varchar(4), YEAR(LastModifedDate)) + ' ' + convert(varchar(3),datename(month, LastModifedDate)) as Dates,
    count(*) as Number

FROM aims.Modification

WHERE CompanyID = @companyID 
    AND LastModifedDate >= DATEADD(month, @numberOfMonths * -1, GETDATE())

GROUP BY convert(varchar(4), YEAR(LastModifedDate)) + ' ' + convert(varchar(3),datename(month, LastModifedDate))

I did try an ORDER BY on the datetime field but got:

Column "aims.Modification.LastModifedDate" is invalid in the ORDER BY clause because it is not contained in either an aggregate function or the GROUP BY clause.

It's also very messy on converting/selecting/group by on the datetime to string. Any advice there would also be very helpful!

Thanks in advance!

Answer 1

This should do:

SELECT  CONVERT(VARCHAR(4),YEAR(LastModifedDate)) + ' ' + 
        CONVERT(VARCHAR(3),DATENAME(MONTH,LastModifedDate)) AS Dates,
        COUNT(*) as Number
FROM aims.Modification
WHERE CompanyID = @companyID 
    AND LastModifedDate >= DATEADD(MONTH,@numberOfMonths * -1,GETDATE())
GROUP BY CONVERT(VARCHAR(4),YEAR(LastModifedDate)) + ' ' + 
         CONVERT(VARCHAR(3),DATENAME(MONTH,LastModifedDate)),
         CONVERT(VARCHAR(6),LastModifedDate,112)
ORDER BY CONVERT(VARCHAR(6),LastModifedDate,112)

Answer 2

SELECT YEAR(LastModifedDate), MONTH(month) as Dates, count(*) as Number
FROM aims.Modification
WHERE CompanyID = @companyID 
    AND LastModifedDate >= DATEADD(month, @numberOfMonths * -1, GETDATE())
GROUP BY YEAR(LastModifedDate), MONTH(LastModifiedDate)
ORDER BY YEAR(LastModifedDate), MONTH(LastModifiedDate)

Keep it simple and make the concatenation in your C# code or report...

Answer 3

Use this to convert your varchar to datetime

 SELECT CONVERT(Datetime,'Jan  2008 ')  

Then sort your column based upon datetime desc. Sorry for short and unfinished answer, Hope it helps.