In 1.6.x and below, mdl_user_students and mdl_user_teachers.
In 1.7.x and above, mdl_role_assignments (with bits from the other mdl_role* tables).
Saludos. Iñaki.
Enrolment
If a student enrolls what tables are updated?
Eztabaida hau blokeatu da eta beraz aurrerantzean ezingo duzu bertan erantzun.