Proses Login PHP

<?php
    require "koneksi.php";
    $nama = $_POST['username'];
    $pass = $_POST['password'];

    $query = "SELECT * from table_login where username = '$nama' AND password = '$pass';";
    $result = mysqli_query($conn, $query);
    $row = mysqli_fetch_array($result);

    if (mysqli_num_rows($result) > 0) {
        $response = array();
        $code = "login_true";
        $message = "Welcome to Apps My Application.";
        array_push($response, array("code"=>$code, "pesan"=>$message));
        echo json_encode(array("Server"=>$response));
    }else{
        $response = array();
        $code = "login_false";
        $message = "Maaf data anda belum terdaftar..!";
        array_push($response, array("code"=>$code, "pesan"=>$message));
        echo json_encode(array("Server"=>$response));
    }
?>