SQL group dates by month

Question

I have a query that returns expiration dates:

    SELECT ci.accountnumber
           , ci.accountname
           , cvu.ExpirationDate
      FROM dbo.clientin         


        

Answer 1

I need to return counts of how many units are due to expire within each month for a 12 month period.

If you mean from the current month forward, then

SELECT
    [YYYY.MM]    = CONVERT(varchar(7), cvu.ExpirationDate, 102),
    CountInMonth = COUNT(*)
FROM dbo.clientinfo ci
JOIN clientvehicleunit cvu ON ci.clientid = cvu.clientid
WHERE cvu.ExpirationDate >= DATEADD(m, DATEDIFF(m,0,getdate()), 0)
  AND cvu.ExpirationDate <  DATEADD(m, DATEDIFF(m,0,getdate())+12, 0)
GROUP BY CONVERT(varchar(7), cvu.ExpirationDate, 102)
ORDER BY [YYYY.MM]

Note: The period is printed in the form [YYYY.MM], e.g. 2011.01