$res = XDB::query('SELECT u.nom, u.prenom, u.promo
FROM auth_user_md5 AS u
WHERE user_id = {?}
GROUP BY u.user_id', $mark_id);
$res = XDB::query('SELECT u.nom, u.prenom, u.promo
FROM auth_user_md5 AS u
WHERE user_id = {?}
GROUP BY u.user_id', $mark_id);