How many distinct colleges are there in the match season?
select count(distinct college) from match_season
Which countries have only one player?
select college from match_season group by college having count(*) = 1
What about at least two?
select college from match_season group by college having count(*) >= 2
Show the result in descending alphabetical order.
select college from match_season group by college having count(*) >= 2 order by college desc