征集最优方法！

[yaoming2002]

大家听我把问题说一说：

table1 :
字段：orderid varchar
state tinyint 固定5种状态：1,2,3,4,5
table2:
字段：orderid 是table1.orderid的的子集
someid varchar 并非唯一标识
num int
id 自增字段

求出当state大于2时的按someid排列的 sum(num) 最大值

[Yang_]

select max(Num) from
(
select b.someid,sum(b.Num) as Num from
table1 a,table2 b
where a.orderid=b.orderid
and a.state>2
) as a

[Yang_]

错了:

select max(Num) from
(
select b.someid,sum(b.Num) as Num from
table1 a,table2 b
where a.orderid=b.orderid
and a.state>2
group by b.someid
) as a

[madyak]

select t2.someid,sum(t1.num)
from table1 t1,table2 t2
where t1.state>2 and t1.orderid=t2.orderid
group by t2.someid
order by t2.someid desc

[wwwho]

求sum(num) 最大值，再按someid排列有意义吗？？？
题目不明确！

[yaoming2002]

to:yang
我试了怎么不行？

Invalid column name 'num' 可num是一个字段啊？

[Yang_]

如果你的字段没有写错，而且用的是SQL SERVER，语句是对的。

你的表述有问题，xjeren(Time)提的。