if(isset($_GET['id'])){
    include('includes/db_connect.php');
    $sql= "SELECT * FROM objects WHERE obj_id=".$_GET['id']."";
    $res = mysqli_query($sql, $db);
    $anzahl = @mysqli_num_rows($res);
    if($anzahl> 0){
    $db->query("DELETE FROM objects WHERE obj_id =".$_GET['id']."");
    echo "Erfolgreich";
    } else{
        echo "Gescheitert";
    }

}