select (tt1.实际金额-tt2.出货金额-tt3.支出总金额) as 利润,tt1.产地,tt1.月
from
(
select sum(实际金额) as 实际金额,产地,datepart(mm,时间) as 月
from t1
group by 产地,datepart(mm,时间)
) tt1,
(
select sum(出货金额) as 出货金额,产地,datepart(mm,时间) as 月
from t2
group by 产地,datepart(mm,时间)
) tt2,
(
select sum(支出总金额) as 支出总金额,产地,datepart(mm,时间) as 月
from t3
group by 产地,datepart(mm,时间)
) tt3
where tt1.产地=tt2.产地 and tt1.月=tt2.月 and tt1.产地=tt3.产地 and tt1.月=tt3.月