USE tempdb
go
if not object_id('进货表') is null
  drop table 进货表
Go
Create table 进货表([商品编码] nvarchar(4), [仓库名字] nvarchar(4),[进货价] decimal(18,1),[进货数量] int,[进货日期] Datetime)
Insert 进货表
select N'0001','aaa',10,20,'2008-5-1 10:05:01' union all
select N'0001','aaa',5,50,'2008-5-2 16:01:02' union all
select N'0002','aaa',6,80,'2008-5-1 10:05:01'
Go

 
if not object_id('销售表') is null
  drop table 销售表
Go
Create table 销售表([商品编码] nvarchar(4),[仓库名字] nvarchar(4),[销售数量] int,[销售日期] Datetime)
Insert 销售表
select N'0001','aaa',10,'2008-5-3 11:01:05' union all
select N'0002','aaa',40,'2008-5-3 15:46:13'
Go


select   ta.[商品编码],ta.[仓库名字], 
ta.[商品编码], 
[数量]=
sum(case   when   tb.出货sum <ta.进货sum-ta.[进货数量]   then   ta.[进货数量]   else   ta.进货sum-tb.出货sum  END)
, 
[库存成本]=sum(case   when   tb.出货sum <ta.进货sum-ta.[进货数量]   then   ta.[进货数量]   else   ta.进货sum-tb.出货sum  END*ta.[进货价])
from   
(select   *
,进货sum=(select   sum([进货数量])   from   进货表   where   [商品编码]=a.[商品编码]   AND [仓库名字]=a.[仓库名字] and   [进货日期]!> a.[进货日期]) 
  from     进货表   a 
)ta 
join 
(select  [仓库名字],[商品编码],SUM([销售数量]) AS [出货sum] from   销售表   GROUP BY [仓库名字],[商品编码] ) tb 
on   ta.[商品编码]=tb.[商品编码]   and ta.[仓库名字]=tb.[仓库名字] AND tb.出货sum <ta.进货sum  
group   by   ta.[商品编码],ta.[仓库名字]

/*
商品编码    仓库名字    商品编码    数量    库存成本
0001    aaa    0001    60    350.0
0002    aaa    0002    40    240.0
*/