create table fen(组名 varchar(10), 得分 int , 时间 datetime)
insert into fen
select 'team1', 99 , '2005.1.1'
union select 'team1', 92, '2005.2.5'
union select 'team1', 95, '2006.1.3'
union select 'team2', 91, '2005.3.2'
union select 'team2', 98, '2005.6.5'
union select 'team2', 96, '2006.3.2'
select 组名,Max( 时间)shijian from fen group by 组名
select fen.* from fen,(select 组名,Max( 时间)shijian from fen group by 组名)tt
where fen.组名=tt.组名 and fen.时间=tt.shijian