declare @表 table 
(订单编号 varchar(6),订单数量 int,订单时间 datetime,物品编号 varchar(4),交货时间 datetime)
insert into @表
select 'A00001',50,'2011-11-02','W001','2011-12-02' union all
select 'A00001',60,'2011-12-02','W001','2011-12-07' union all
select 'A00001',70,'2012-01-02','W002','2012-02-04' union all
select 'A00002',80,'2011-12-02','W002','2011-12-02' union all
select 'A00003',90,'2011-12-02','W002','2011-12-02'

select 订单编号,物品编号,订单数量=sum(订单数量) 
from @表 group by 订单编号,物品编号

/*
订单编号   物品编号 订单数量
------ ---- -----------
A00001 W001 110
A00001 W002 70
A00002 W002 80
A00003 W002 90
*/