create table tb
(
  ID int,
  FBILLNO varchar(20),
  num int ,
  fdate varchar(10)
)

insert into tb
select 1,'lxm12010001', 12, '2012-1-1' union all
select 1,'lxm12010001', 13, '2012-1-1' union all  
select 1,'lxm12010001', 10, '2012-1-1' union all
select 2,'lxm12010002', 50, '2012-1-5' union all
select 2,'lxm12010002', 60, '2012-1-5' union all
select 3,'lxm12010003', 10, '2012-1-6' union all
select 4,'lxm12010004', 10, '2012-1-7'

Select * From tb Where FBILLNO In (Select FBILLNO From tb Group By FBILLNO Having Count(*)>1)

ID          FBILLNO              num         fdate
----------- -------------------- ----------- ----------
1           lxm12010001          12          2012-1-1
1           lxm12010001          13          2012-1-1
1           lxm12010001          10          2012-1-1
2           lxm12010002          50          2012-1-5
2           lxm12010002          60          2012-1-5

------解决方案--------------------
SQL code
 select ID,FBILLNO,NUM,fdate from (
Select *,(select COUNT(1) from tb where   FBILLNO=t.FBILLNO   )as co From tb   t 
 )s   where  co>1