select a.no,a.usr,sum(b.money2),sum(c.money3) from 表1 a,表2 b,表3 c where a.no=b.no and b.no=c.no group by a.no,a.usr
select a.no,a.usr,sum(b.money2),sum(c.money3) from 表1 a left join 表2 b on where a.no=b.no left join 表3 c on a.no=c.no group by a.no,a.usr
select 表1.no,user,money2,money3 from 表1 inner join (select 表2.no,Sum(money2) as money2,Sum(money3) as money3 from 表2 inner join 表3 on 表2.no=表3.no group by 表2.no) as AA on 表1.no=AA.no
楼上的,这样作还是会重复计算啊,而且用left join比较合适吧。
select t1.no,t1.user,t2.sm2,t3.sm3 from 表1 t1 left join (select no,sum(money2) sm2 from 表2 group by no) t2 on t1.no=t2.no left join (select no,sum(money3) sm3 from 表3 group by no) t3 on t1.no=t3.no试试这样呢。
from 表1 a,表2 b,表3 c
where a.no=b.no and b.no=c.no
group by a.no,a.usr
from 表1 a left join 表2 b on where a.no=b.no left join 表3 c
on a.no=c.no
group by a.no,a.usr
from 表1 inner join
(select 表2.no,Sum(money2) as money2,Sum(money3) as money3
from 表2 inner join 表3 on 表2.no=表3.no
group by 表2.no) as AA
on 表1.no=AA.no
from 表1 t1 left join (select no,sum(money2) sm2 from 表2 group by no) t2 on t1.no=t2.no
left join (select no,sum(money3) sm3 from 表3 group by no) t3 on t1.no=t3.no试试这样呢。
不知道大家有什么sql编程方面书可以推荐一下,最好有很多实例的那种!!!