SELECT u.*

                        FROM user u

                        WHERE u.id IN (

                            SELECT u2.id FROM

                            user u2

                            JOIN (SELECT DISTINCT eu1_u.id

              FROM user eu1_u

            JOIN user_enrolments eu1_ue ON eu1_ue.userid = eu1_u.id

JOIN enrol eu1_e ON (eu1_e.id = eu1_ue.enrolid AND eu1_e.courseid = '5')

           WHERE eu1_u.deleted = 0 AND eu1_u.id <> '153' AND eu1_ue.status = '0' AND eu1_e.status = '0' AND eu1_ue.timestart < 1415115100 AND (eu1_ue.timeend = 0 OR eu1_ue.timeend > 1415115100)) je ON je.id = u2.id

                            LEFT JOIN forum_subscriptions s ON s.userid = u2.id

                            LEFT JOIN forum_discussion_subs ds ON ds.userid = u2.id

                            WHERE

                              s.forum = '33'

                            OR

                              (ds.forum = '33' AND ds.preference <> '-1')

                        )

                        ORDER BY u.email ASC;