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

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