去除重复的数据列

[ljb0901]

select AdUserId,AdRegId ,AdRegIp,AdTime,LastLogonIP,users.Age from
UserAccounts as users,Adinfo where RegType='1' and users.userid=Adinfo.AdRegId
and LastLogonIP!='' and Adtime between '2009-3-26 0:00:00' and '2009-3-27 0:00:00'
and ADSiteID=1001
我想让AdRegId中显示的数据不重复

[Teng_s2000]

group by AdRegIp  having count(AdRegIp)=1

[dawugui]

select t.* from tb t where (其他条件) and adtime = (select min(adtime) from tb where (其他条件) and adregid = t.adregig)

select t.* from tb t where (其他条件) and adtime = (select max(adtime) from tb where (其他条件) and adregid = t.adregig)

[htl258_Tony]

select AdUserId,AdRegId ,AdRegIp,AdTime,LastLogonIP,users.Age 
from UserAccounts as users,Adinfo t
where RegType='1' and users.userid=Adinfo.AdRegId 
  and LastLogonIP!='' and Adtime between '2009-3-26 0:00:00' and '2009-3-27 0:00:00' 
  and ADSiteID=1001 
  and not exists(select 1 from Adinfo where Adregid=t.Adregid and Adtime>t.Adtime)

[jdbcodbc]

还是没用啊

[jdbcodbc]

dawugui 能在我原来那个代码上修改下吗?
htl258 发的这个语法错误

[Teng_s2000]

ls的就不会把表数据和结构都用sql整出来?
还得让dawugui自己慢慢添加数据!

[jdbcodbc]

select * from def where adregid in (select min(adregid) from def group by adregip having count(adregid)>1 )
union
select * from def where adregid in (select max(adregid) from def group by adregip having count(adregid)=1 )