$supprimer = mysqli_query($bdd, "SELECT vu.id FROM detail, vu, membre WHERE detail.id=vu.id_serie and vu.id_membre=membre.id and membre.id=".$_SESSION['id']."  ORDER BY vu.id DESC LIMIT 6,1") or die(mysqli_error($bdd));

		$msg = mysqli_fetch_array($supprimer);
		$id_msg = $msg['id'];
		
		if ($id_msg != NULL)
		{
			mysqli_query($bdd, 'DELETE FROM vu WHERE id<='.$id_msg) or die(mysqli_error($bdd));
		}

DELETE
FROM vu
WHERE id_serie NOT IN (
	SELECT t.id_serie
	FROM (
		SELECT vu.id_serie,row_number() over(PARTITION BY vu.id ORDER BY vu.id) rn
		FROM detail, vu, membre
		WHERE detail.id=vu.id_serie AND vu.id_membre=membre.id AND membre.id=$_SESSION['id']
		ORDER BY vu.id) t
	WHERE t.rn <=6
)

mysqli_query($bdd, "DELETE from vu WHERE id_serie not in (SELECT * FROM detail, vu, membre WHERE detail.id=vu.id_serie and vu.id_membre=membre.id and membre.id=".$_SESSION['id']."  ORDER BY vu.id DESC LIMIT 6)")or die(mysqli_error($bdd));

delete from latable where id not in (select id from latable where le predicat order by colonnequivabien limit 6)