I have some SQL that produces data in the following format:

Arsenal,van Persie
Arsenal,Gervinho
Aston Villa,Heskey
Aston Villa,Agbonlahor
Aston Villa,Bent
etc

(It isn't comma separated, the club and player are in separate columns)
(Also, it isn't really about football but I didn't want to use students' names )

I need to produce a report looking like this:

Arsenal,van Persie,Gervinho
Aston Villa,Heskey,Agbonlahor,Bent
etc

The number of players needed to be included will vary between clubs. Any ideas how to do it?

I've tried creating the report as a matrix, but then every players' name appears across the top!

Cheers.