public function update(Modele $mod)
 {
     $req = $this->_db->prepare("UPDATE modele SET nomModele=:nom, qteStock=:qte, prix=:px, tauxRemise=:tx WHERE idModele=:id");
     $req->execute(array(":nom" => $mod->getNomModele(), ":qte" => $mod->getQteStock(), ":px" => $mod->getPrix(), ":tx" => $mod->getTauxRemise(), ":id" => $mod->getIdModele()));
 }