问修改MySQL语句以允许更新

EN

UPDATE mdl_user 
JOIN (
SELECT DISTINCT u.id AS userid, c.id AS courseid
FROM mdl_user u
    JOIN mdl_user_enrolments ue ON ue.userid = u.id
    JOIN mdl_enrol e ON e.id = ue.enrolid
    JOIN mdl_role_assignments ra ON ra.userid = u.id
    JOIN mdl_context ct ON ct.id = ra.contextid
        AND ct.contextlevel =50
    JOIN mdl_course c ON c.id = ct.instanceid
        AND e.courseid = c.id
    JOIN mdl_role r ON r.id = ra.roleid
        AND r.shortname =  'student'
WHERE e.status =0
AND u.suspended =0
AND u.deleted =0
AND ue.status =0
AND courseid =1538
) AS a
ON a.userid = mdl_user.id
SET email = 'users@domain.com'