Retrieve top 48 unique records from database based on a sorted Field - sql

Question

I have database table that I am after some SQL for (Which is defeating me so far!)
Imagine there are 192 Athletic Clubs who all take part in 12 Track Meets per season.
So that is 2304 individual performances per season (for example in the 100Metres)
I would like to find the top 48 (unique) individual performances from the table, these 48 athletes are then going to take part in the end of season World Championships.
So imagine the 2 fastest times are both set by "John Smith", but he can only be entered once in the world champs. So i would then look for the next fastest time not set by "John Smith"... so on and so until I have 48 unique athletes..
hope that makes sense.
thanks in advance if anyone can help
PS
I did have a nice screen shot created that would explain it much better. but as a newish user i cannot post images.
I'll try a copy and paste version instead...
ID AthleteName AthleteID Time
1 Josh Lewis 3 11.99
2 Joe Dundee 4 11.31
3 Mark Danes 5 13.44
4 Josh Lewis 3 13.12
5 John Smith 1 11.12
6 John Smith 1 12.18
7 John Smith 1 11.22
8 Adam Bennett 6 11.33
9 Ronny Bower 7 12.88
10 John Smith 1 13.49
11 Adam Bennett 6 12.55
12 Mark Danes 5 12.12
13 Carl Tompkins 2 13.11
14 Joe Dundee 4 11.28
15 Ronny Bower 7 12.14
16 Carl Tompkin 2 11.88
17 Nigel Downs 8 14.14
18 Nigel Downs 8 12.19
Top 4 unique individual performances
1 John Smith 1 11.12
3 Joe Dundee 4 11.28
5 Adam Bennett 6 11.33
6 Carl Tompkins 2 11.88

Answer 1

Basically something like this:
select top 48 *
from (
select athleteId,min(time) as bestTime
from theRaces
where raceId = '123' -- e.g., 123=100 meters
group by athleteId
) x
order by bestTime

Answer 2

try this --
select x.ID, x.AthleteName , x.AthleteID , x.Time
(
select rownum tr_count,v.AthleteID AthleteID, v.AthleteName AthleteName, v.Time Time,v.id id
from
(
select
tr1.AthleteName AthleteName, tr1.Time time,min(tr1.id) id, tr1.AthleteID AthleteID
from theRaces tr1
where time =
(select min(time) from theRaces tr2 where tr2.athleteId = tr1.athleteId)
group by tr1.AthleteName, tr1.AthleteID, tr1.Time
having tr1.Time = ( select min(tr2.time) from theRaces tr2 where tr1.AthleteID =tr2.AthleteID)
order by tr1.time
) v
) x
where x.tr_count < 48