SELECT DISTINCT
	u.id,
	u.username,
	u.firstname,
	u.lastname,
	u.email
FROM
	mdl_user u
LEFT JOIN mdl_user_enrolments e ON u.id = e.userid
LEFT JOIN mdl_role_assignments a ON u.id = a.userid
WHERE
	u.id NOT IN (
		SELECT
			userid
		FROM
			mdl_user_enrolments
	)
AND u.id NOT IN (
	SELECT
		userid
	FROM
		mdl_role_assignments
	WHERE
		roleid != 11
)
AND u.deleted = 0
ORDER BY
	u.id;