create table taba(id int, date datetime, bouns int)
insert into taba select 1,'2006-1-1',100
union all select 1,'2006-1-1',100
union all select 1,'2006-1-4',100
union all select 1,'2006-1-1',100
union all select 1,'2007-12-1',100
union all select 1,'2007-1-12',100
union all select 2,'2006-1-1',100
union all select 1,'2006-1-1',100
union all select 2,'2006-1-1',100
union all select 1,'2006-1-1',100
union all select 2,'2006-1-1',100
union all select 1,'2006-3-1',100
union all select 1,'2006-3-11',100
union all select 3,'2006-1-1',100
union all select 1,'2006-1-1',100
union all select 3,'2007-7-1',100
go
select id,CONVERT(varchar(6),date,112)as date,sum(bouns)as bouns
from taba group by id,CONVERT(varchar(6),date,112)