I cant really help you creat this, but if I was to do this, I would try to find a program that would extract the cddb info to a temp file, or file for back up. And in that file would be the all of the info seperated by a ; or : or whatever is easy for php to understand, than php or your script reads that info and enters it into your mysql data base.
I would assume your hardest part would be getting the info to extract to a file. If you know php well enough, the rest should be simple. Hmm you probably could create a simple perl or c++ script to do that. The only hard part there would be if perl and c++ could talk to the mysql server.
That may be confusing.
Possiblities
Freshmeat has a huge list of scripts for ID3 tag editing and reading just look through them =
http://freshmeat.net/search/?q=ID3&s...&Go.x=0&Go.y=0
JACKPOT =
http://freshmeat.net/projects/naamah/
shit, you can really only use it to get the cddb info if you have a MS2000 or XP and IE.. Look at the other post about cddb and mysql in this forum for more scripts.
**edit**
main website
http://www.tiscalinet.ch/nick/naamah/
above is extactly what you need!
Little old, but good idea =
http://freshmeat.net/projects/anus/
May be more editable =
http://cddb-py.sourceforge.net/