how to populate Postgresql base with users ?

Dear Sirs, I want to implement PPTP server (either mpd or poptop) with CHAP+MPPE authentication against freeradius. I've successfully configured freeradius+postgresql, but I'm lost in the database, I've no idea how to populate database. Can anyone provide me some dump for example ? (including sample user, sample password and sample parameters for connection) Thanks!