postgresql7.1 select dotlrn_member_rels_approved.rel_id, dotlrn_member_rels_approved.rel_type, dotlrn_member_rels_approved.role, dotlrn_member_rels_approved.user_id, registered_users.first_names, registered_users.last_name, registered_users.email from registered_users, dotlrn_member_rels_approved where dotlrn_member_rels_approved.community_id = :community_id and dotlrn_member_rels_approved.user_id = registered_users.user_id order by ( CASE WHEN role = 'instructor' THEN 1 WHEN role = 'admin' THEN 2 WHEN role = 'teaching_assistant' THEN 3 WHEN role = 'course_assistant' THEN 4 WHEN role = 'student' THEN 6 WHEN role = 'member' THEN 7 END ) asc, $order_by