errore query

[techno]

ecco la connessione:

class database{

    public $host="localhost";
    public $user="root";
    public $password="xxxxxxxx";
    public $db="database";
    public $dbcomm;
    public $result;
    
    function connect(){
        $this->dbcomm=new mysqli($this->host,$this->user,$this->password,$this->db) or die (mysqli_error());
    }
    
    function query($query){
        $this->result=mysqli_query($this->dbcomm,$query) or die (mysqli_error());
        return $this->result;
    }
    
    function disconnect(){
        mysqli_close($this->dbcomm);
    }
}

    $database=new database;
    $database->connect();
    $idshop=$_COOKIE["IDShop_Concadoro"];
    
    $sql="SELECT IDarticolo, Quantita, magazzino.ID as ida, Categoria, Articolo, Prezzo FROM cart, magazzino WHERE IDShop='$idshop' AND magazzino.ID=IDarticolo";

    $query=$database->query($sql); 

questo e tutto