Update avec Mysql

<?php
$conect = new mysqli ("localhost", "nom","mdp","mabase");
$req = "SELECT * FROM fournisseurs WHERE four_id=".$_GET['numart'];
$resultat = $conect->query($req);
$un = $resultat-> fetch_array() ;
?>

    <form name="form1" method="GET" action="valide_modif_four.php">
    Nom du fournisseur: <input type="text" name="nom" value="<?php echo $un['four_nom'] ?>">
    Description: <input type="text" name="tel" value="<?php echo $un['four_tel'] ?>">
    Prix: <input type="text" name="ville" value="<?php echo $un['four_ville'] ?>">
    Id: <input type="text" name="idfour" value="<?php echo $un['four_id']?>">
    
<br/>
    <button type="submit">Valider</button>

</form>

    $conect = new mysqli ("localhost", "nom","mdp","mabase");
    
	$nom=$_GET['nom'];
	$tel=$_GET['tel'];
	$ville=$_GET['ville'];
	$id=$_GET['idfour'];
    $numart=$_GET['numart'];
	
	$requete= $conect->prepare("UPDATE fournisseurs SET four_id='$id', four_nom='$nom', four_tel='$tel', four_ville='$ville' WHERE four_id='$numart'");
	$requete->execute();
?>