Hvordan får man summen af ​​alle kolonneværdier i den sidste række af et resultatsæt?

Lav en forening, hvor du gentager den samme forespørgsel, men uden grupperingen:

select Title, Jan, Feb, Mar
from (
  select Master_Code as Title, SUM(Jan) as Jan, SUM(Feb) as Feb, SUM(Mar) as Mar
  from dbo.foobar
  WHERE Participating_City = 'foofoo'
  GROUP BY Master_Code ORDER BY Master_Code ASC
) x
union all
select 'Total', SUM(Jan) as Jan, SUM(Feb) as Feb, SUM(Mar) as Mar
from dbo.foobar
WHERE Participating_City = 'foofoo'