I can't find the database table that stores the course roster data-- i.e. which users are enrolled in which courses. Can someone help?
I am assuming you are asking about Moodle 1.9 - so that would be the mdl_role_assignments table which will likely lead to more questions about contexts. You will probably find it helpful to know that contextlevel 50 refers to courses (off the top of my head - you may want to double check in /lib/accesslib.php). Peace - Anthony