Simplifying quey in compute_users_points function

classes/summary.php

@@ -186,8 +186,8 @@ class mod_attendance_summary {
             $where .= ' AND ats.groupid = 0';
         }
 
-        $sql = "SELECT userid, COUNT(*) AS numtakensessions, SUM(grade) AS points, SUM(maxgrade) AS maxpoints
-                 FROM (SELECT atl.studentid AS userid, ats.id AS sessionid, stg.grade, stm.maxgrade
+        $sql = " SELECT atl.studentid AS userid, COUNT(DISTINCT ats.id) AS numtakensessions,
+                        SUM(stg.grade) AS points, SUM(stm.maxgrade) AS maxpoints
                    FROM {attendance_sessions} ats
                    JOIN {attendance_log} atl ON (atl.sessionid = ats.id)
                    JOIN {attendance_statuses} stg ON (stg.id = atl.statusid AND stg.deleted = 0 AND stg.visible = 1)
@@ -203,8 +203,7 @@ class mod_attendance_summary {
                     AND ats.sessdate >= :cstartdate
                     AND ats.lasttakenby != 0
                     {$where}
-                      ) sess
-                GROUP BY userid";
+                GROUP BY atl.studentid";
         $this->userspoints = $DB->get_records_sql($sql, $params);
     }