Подключение к БД MySQL. Xamarin Studio: C#-PHP-MySQL

<?php
class DB_CONNECT {
    function __construct() {
        $this->connect();
    }
    function __destruct() {
        $this->close();
    }
    function connect() {
        require 'db_config_android.php';
        $con = mysql_connect(DB_SERVER, DB_USER, DB_PASSWORD) or die(mysql_error()); 
        $db = mysql_select_db(DB_DATABASE) or die(mysql_error()) or die(mysql_error());
        return $con;
    }
    function close() {
        mysql_close();
    }
}
?>

<?php
 
$response = array();
 
require 'db_connect_android.php';
 
$db = new DB_CONNECT();
 
$result = mysql_query("SELECT * FROM Students") or die(mysql_error());
 
if (mysql_num_rows($result) > 0) {
    $response["students"] = array();
 
    while ($row = mysql_fetch_array($result)) {
        $product = array();
        $product["ID"] = $row["ID"];
        $product["Name"] = $row["Name"];
        $product["Surname"] = $row["Surname"];
        $product["Lastname"] = $row["Lastname"];
 
        array_push($response["products"], $product);
    }
    $response["success"] = 1;
 
    echo json_encode($response);
} else {
    $response["success"] = 0;
    $response["message"] = "No students found";
 
    echo json_encode($response);
}
?>