这个sql语句怎么写？在线等

[aa323]

表结构为

id userid aMonth aNum invoice aDate
1 abc 9 200 No.11111 2009-9-12
2 www 10 900 No.12222 2009-10-8
3 abc 10 800 No.11111 2009-9-12
3 abc 12 1100 No.13333 2009-12-12

这里是一张发票做了几次输入，如发票号为No.12587，所以userid和aDate会是一样的
现在要根据发票号统计出abc用户的aNum总数来，并取出aDate

希望最后显示出
userid sum(aNum) aDate invoice
abc 1000 2009-9-12 No.11111

sql语句应该怎么写呢？用了group by invoice 好像就取不出aDate？本人菜鸟，请高手指点，谢谢！

[--小F--]

select
  userid,sum(anum) as anum,adate,invoice
from
  tb
where
  userid='abc'
group by
  userid,adate,invoice

[ACMAIN_CHM]

select userid,sum(aNum),invoice,aDate
from 表
group by userid,invoice,aDate

[--小F--]

--这样?
----------------------------------------------------------------
-- Author  :fredrickhu(小F，向高手学习)
-- Date    :2010-01-23 21:40:28
-- Version:
--      Microsoft SQL Server 2005 - 9.00.4035.00 (Intel X86) 
--	Nov 24 2008 13:01:59 
--	Copyright (c) 1988-2005 Microsoft Corporation
--	Developer Edition on Windows NT 5.1 (Build 2600: Service Pack 3)
--
----------------------------------------------------------------
--> 测试数据：[tb]
if object_id('[tb]') is not null drop table [tb]
go 
create table [tb]([id] int,[userid] varchar(3),[aMonth] int,[aNum] int,[invoice] varchar(8),[aDate] datetime)
insert [tb]
select 1,'abc',9,200,'No.11111','2009-9-12' union all
select 2,'www',10,900,'No.12222','2009-10-8' union all
select 3,'abc',10,800,'No.11111','2009-9-12' union all
select 3,'abc',12,1100,'No.13333','2009-12-12'
--------------开始查询--------------------------
select
  userid,sum(anum) as anum,adate,invoice
from
  tb
where
  userid='abc'
group by
  userid,adate,invoice
having count(1)>1
----------------结果----------------------------
/* userid anum        adate                   invoice
------ ----------- ----------------------- --------
abc    1000        2009-09-12 00:00:00.000 No.11111

(1 行受影响)
*/