这样的SQL语句该怎么写呢

[redfox105]

表ku8_ip 里有ip,addtime字段
IP字段是有重复的，如何获取唯一的IP和时间（时间要最新的那个）
像下面这样显示
ip addtime
192.168.161.1 2004-4-8
202.193.64.34 2005-7-8
.
.
.
注意IP不能重复

[lsxaa]

select ip,max(addtime) as addtime
from ku8_ip
group by ip

[zengzhengliang]

select ip,max(addtime) as lasttime
from ku8_ip gruop by ip

[lvenx]

select DISTINCT ip,max(addtime) as addtime
from ku8_ip
group by ip

[vinsonshen]

select ip,max(addtime) as New_addtime
from ku8_ip
group by ip