SQL按月分组并添加15分钟

Question

I have a table with data every 15mins.

I have this query :

Select Sum(Value) From MyTable Group By month(myDate), year(myDate)

However the result is not what i want because I have values from

'2013-01-01 00:00:00.000' to '2013-01-31 23:45:00.000' and I need to have values from

'2013-01-01 00:15:00.000' and '2013-02-01 00:00:00.000'

How can I change the request to have the correct date range ?

Thanks

Answer 1

Use DATEADD method:

SELECT Sum(Value)
FROM MyTable
GROUP BY MONTH(DATEADD(minute,15,myDate)), YEAR(DATEADD(minute,15,myDate))