select '2012-12' as date,b.name,sum(isnull(score,0))score
from #t a right join
(select distinct name from #t) b on a.name=b.name
and convert(varchar(7),date)='2012-12'
group by convert(varchar(7),date),b.name
select convert(varchar(7),date) as date,b.name,sum(isnull(score,0))score
from table a right join
(select distinct name from table) b on a.name=b.name
where convert(varchar(7),date)='2012-12'
group by convert(varchar(7),date),name