use Tempdb
go
--> --> 
 
if not object_id(N'Tempdb..#T1') is null
    drop table #T1
Go
Create table #T1([帐户] int,[商品编号] int,[数量] int)
Insert #T1
select 101,1001,5 union all
select 102,1001,3
Go
declare @s nvarchar(4000)
set @s=''
Select     @s=@s+N','+quotename(帐户)+N'=max(case when 帐户=N'+quotename(帐户,'''')+N' then 数量 else '''' end)'

from #T1 group by 帐户
--顯示生成語句
print N'select 商品编号'+@s+N' from #T1 group by 商品编号'

exec(N'select 商品编号'+@s+N' from #T1 group by 商品编号')

go

--SQL2005 

declare @s nvarchar(4000)
Select     @s=isnull(@s+',','')+quotename(帐户) from #T1 group by 帐户
exec('select * from #T1 as a pivot (max(数量) for 帐户 in('+@s+'))b')

/*
商品编号    101    102
1001    5    3
*/

------解决方案--------------------
SQL code
----------------------------
-- Author  :fredrickhu(小F，向高手学习)
-- Date    :2011-12-30 12:55:07
-- Version:
--      Microsoft SQL Server 2008 R2 (RTM) - 10.50.1617.0 (Intel X86) 
--    Apr 22 2011 11:57:00 
--    Copyright (c) Microsoft Corporation
--    Enterprise Evaluation Edition on Windows NT 6.1 <X64> (Build 7600: ) (WOW64)
--
----------------------------
--> 测试数据：[tb]
if object_id('[tb]') is not null drop table [tb]
go 
create table [tb]([帐户] int,[商品编号] int,[数量] int)
insert [tb]
select 101,1001,5 union all
select 102,1001,3
--------------开始查询--------------------------
declare @sql varchar(8000)
set @sql = 'select 商品编号 '
select @sql = @sql + ' , max(case 帐户 when ''' + ltrim(帐户) + ''' then 数量 else 0 end) [' + ltrim(帐户) + ']'
from (select distinct 帐户 from tb) as a
set @sql = @sql + ' from tb group by 商品编号'
exec(@sql) 

----------------结果----------------------------
/* 商品编号        101         102
----------- ----------- -----------
1001        5           3

(1 行受影响)
*/