按日期分组统计的问题

[ahking]

主表
rq f1 subID
2012-1-1 6 1
2012-1-1 7 2
2012-1-2 3 1
.........

id关系表
maiID subID
1 1
1 2
.............

要求统计按mainID每天统计f1的和，该如何做？

[中国风]

select 
a.rq,b.maiID,
sum(a.f1) as f1
from 主表 as a
inner join 关系表 as b on a.subID=b.subID
group by a.rq,b.maiID

[yuanmeixiang]

select sum(f1) max(rq) from a join b on a.subID = b.subID group by rq

[yuanmeixiang]

select sum(f1), rq from a join b on a.subID = b.subID group by rq