GROUP BY GROUPING SETS for a selected month and for year to date

Question

Below is a code example to demonstrate this question:
declare @test table (ID int, Quantity int, Day date);
insert into @test values
(4, 500, '1/18/2014'),
(4, 550, '1/28/2014'),
(7, 600, '1/10/2014'),
(7, 750, '1/11/2014'),
(7, 800, '1/20/2014'),
(1, 100, '1/2/2014'),
(1, 125, '1/10/2014'),
(8, 300, '1/7/2014'),
(9, 200, '1/17/2014'),
(9, 100, '1/22/2014'),
(4, 900, '2/18/2014'),
(4, 550, '2/28/2014'),
(7, 600, '2/10/2014'),
(7, 700, '2/11/2014'),
(7, 800, '2/20/2014'),
(1, 100, '2/2/2014'),
(1, 150, '2/10/2014'),
(8, 300, '2/7/2014'),
(9, 200, '2/17/2014'),
(9, 100, '2/22/2014'),
(4, 500, '3/18/2014'),
(4, 550, '3/28/2014'),
(7, 600, '3/10/2014'),
(7, 750, '3/11/2014'),
(7, 800, '3/20/2014'),
(1, 100, '3/2/2014'),
(1, 325, '3/10/2014'),
(8, 300, '3/7/2014'),
(9, 200, '3/17/2014'),
(9, 100, '3/22/2014'),
(4, 500, '4/18/2014'),
(4, 550, '4/28/2014'),
(7, 100, '4/10/2014'),
(7, 750, '4/11/2014'),
(7, 800, '4/20/2014'),
(1, 100, '4/2/2014'),
(1, 325, '4/10/2014'),
(8, 300, '4/7/2014'),
(9, 200, '4/17/2014'),
(9, 100, '4/22/2014'),
(4, 500, '5/18/2014'),
(4, 550, '5/28/2014'),
(7, 600, '5/10/2014'),
(7, 750, '5/11/2014'),
(7, 50, '5/20/2014'),
(1, 100, '5/2/2014'),
(1, 325, '5/10/2014'),
(8, 300, '5/7/2014'),
(9, 200, '5/17/2014'),
(9, 100, '5/22/2014');
--detail
select *
from @test;
--aggregation
select
TotalQuantity = sum(Quantity),
[Month] = month(Day)
from @test
group by
grouping sets
(month(Day)),
(year(Day))
go
This is the aggregation query result:
However, the desired result is to return only two rows: one row for month 3 and the other row for year to date (in the picture above YTD is the row that appears with {null} in the Month column).  Is there a way to achieve this goal by modifying the
sample code above?  The requirement is to only read the data once (do not want a solution that involves a UNION which implies reading the data twice).

Answer 1

you can add required filters in having clause. Here is the query -
select
TotalQuantity = sum(Quantity),
[Month] = month(Day)
from @test
group by
grouping sets
(month(Day)),
(year(Day))
having
month(Day) = 3 or month(Day) is null;