SQL Server : how to group values by month interval with offset - sql

Question

I have a query that groups aggregated sum values by month.
This is the query:
Declare #IsByStatus bit
Set #IsByStatus = 0
SELECT
CAST((DATEDIFF(month, '2012-01-01T06:00:00', datTimeStamp)) AS int) AS [Index] ,
Min(datTimeStamp) as [From],
Max(datTimeStamp) as [To],
Sum(CASE CAST(intIO_ID AS nvarchar(100))
WHEN N'284' THEN Value ELSE NULL END) AS [286]
FROM
[IOValuesFn](#IsByStatus) IOValues
WHERE
datTimeStamp >= '2012-01-01T06:00:00'
AND datTimeStamp < '2013-01-01T05:59:59'
AND intIO_ID IN (284)
GROUP BY
CAST ((DATEDIFF(Month,'2012-01-01T06:00:00', datTimeStamp)) AS int)
ORDER BY
[From]
And this is the result:
Index From To 286
0 2012-01-07 07:00:00.000 2012-01-31 23:00:00.000 142579.898864746
1 2012-02-01 00:00:00.000 2012-02-29 23:00:00.000 139486.498001099
2 2012-03-01 00:00:00.000 2012-03-31 23:00:00.000 99516.3022232056
3 2012-04-01 00:00:00.000 2012-04-30 23:00:00.000 84597.599899292
4 2012-05-01 00:00:00.000 2012-05-31 23:00:00.000 67085.2983112335
5 2012-06-01 00:00:00.000 2012-06-30 23:00:00.000 67768.9982643127
6 2012-07-01 00:00:00.000 2012-07-31 23:00:00.000 121100.264842987
7 2012-08-01 00:00:00.000 2012-08-31 23:00:00.000 165768.90776825
8 2012-09-01 00:00:00.000 2012-09-30 23:00:00.000 97441.7333068848
9 2012-10-01 00:00:00.000 2012-10-31 23:00:00.000 153764.736312866
10 2012-11-01 00:00:00.000 2012-11-30 23:00:00.000 153601.413961411
11 2012-12-01 00:00:00.000 2012-12-31 23:00:00.000 142521.07028389
12 2013-01-01 00:00:00.000 2013-01-01 05:00:00.000 1192.32000732422
Now I want to do the similar logic, that will also insert an offset in the month start-end time.
e.g. the first period will start on january 1'st on 11:00 AM and will end at february 1 10:59:59 AM.
Same goes for each subsequent month.
Thanks in advance for your help, Omer

Answer 1

Have a look at the example below. The trick is to add the negative amount of offset such that any hour prior to 11am on the first day of the month is "pushed" into the prior month.
Schema Setup:
create function iovaluesfn(#isbystatus bit) returns table as return
select datTimeStamp = '20130101 10:50', intIO_ID = 284, Value = 1 union all
select '20130101 11:00', 284, 1 union all
select '20130102 11:00', 284, 2 union all
select '20130301 11:00', 284, 3 union all
select '20130401 11:00', 284, 4 union all
select '20120501 11:00', 284, 5 union all
select '20120601 11:00', 284, 6 union all
select '20120101 11:00', 284, 7 union all
select '20120102 11:00', 284, 8 union all
select '20120101 11:01', 284, 9 union all
select '20120101 10:59', 284,10 union all -- ** this value is counted in Dec 2011
select '20120101 11:00', 284,11 union all
select '20120101 11:01', 281,12 union all
select '20120101 10:59', 281,13 union all
select '20120101 11:00', 281,14
GO
Query:
Declare #IsByStatus bit;
Set #IsByStatus = 0;
;with IOValues as (
select DATEADD(hour, -11, datTimeStamp) datTimeStamp, intIO_ID, Value
FROM [IOValuesFn](#IsByStatus)
WHERE datTimeStamp >= '2012-01-01T06:00:00' AND datTimeStamp < '2013-01-01T05:59:59'
AND intIO_ID IN (284)
)
SELECT CAST((DATEDIFF(month,'2012-01-01T06:00:00',datTimeStamp)) AS int) AS [Index],
Min(datTimeStamp) as [From],
Max(datTimeStamp) as [To],
Sum(CASE CAST(intIO_ID AS nvarchar(100))
WHEN N'284' THEN Value ELSE NULL END) AS [286]
FROM IOValues
GROUP BY CAST ((DATEDIFF(Month,'2012-01-01T06:00:00',datTimeStamp))AS int)
order by [From];
Results:
| INDEX | FROM | TO | 286 |
----------------------------------------------------------
| -1 | December, 31 2011 | December, 31 2011 | 10*** |
| 0 | January, 01 2012 | January, 02 2012 | 35 |
| 4 | May, 01 2012 | May, 01 2012 | 5 |
| 5 | June, 01 2012 | June, 01 2012 | 6 |
SQL Fiddle Demo