请高手帮忙,求一sql

时间排列,表格式如下

emp_id card_id sing_time
06F00734 00734 2007-03-23 10:21:43
06F00734 00734 2007-03-23 10:23:00
06F00734 00734 2007-03-23 10:24:49
06F00747 00747 2007-03-23 12:34:52
01F00020 00020 2007-03-23 12:35:52
04F00413 00413 2007-03-23 12:36:25
03M00262* 00262* 2007-03-23 12:36:27
02M00093* 00093* 2007-03-23 12:36:27
02F00137 00137 2007-03-23 12:36:29
02F00128 00128 2007-03-23 12:36:30
02F00127 00127 2007-03-23 12:36:31
02F00114 00114 2007-03-23 12:36:32

用条sql得到如下格式
emp_id card_id t_day date1(第一次时间) date2(最后一次时间)
06F00734 00734 2007-03-23 10:21:43 10:24:49

先感谢各位高手帮忙

看这样行不行
select emp_id， card_id，max(sign_time) as date1,min(sign_time) as date2 
from table
group by emp_id， card_id

select emp_id,card_id,convert(varchar(10),sing_time,120) as t_day,
min(substring(convert(varchar(19),sing_time,120),12,8)) as time1,
max(substring(convert(varchar(19),sing_time,120),12,8)) as time2
from table1
group by emp_id,card_id,convert(varchar(10),sing_time,120)

以上语句适合于MS SQL Server 2000　以上版本。