在AppEngine上部署应用程序后无法连接MySQL

Can someone help me fix this , i wrote a simple code to test MySQL connection , it work on locally but can't connect MySQL after deployed it on app engine.

File app.yaml:

application: testmysql07

version: 1

runtime: php55

api_version: 1

threadsafe: yes

handlers:

- url: /favicon\.ico
  static_files: favicon.ico
  upload: favicon\.ico

- url: .*
  script: main.php

File main.php:

<?php

$hostname     = "localhost"; 

$username     = "root";

$password     = "";

$databasename = "web_bb"; 

$conn = mysql_connect($hostname,$username,$password,$databasename) or die("Can't connect MySQL");

    echo "Successful </br>";

mysql_select_db($databasename,$conn);

?>

Sorry i'm not good in speaking english

To connect to your local MySQL database during development, you'll need to

  1. Enable billing for your app. This allows you to use sockets to connect to remote servers.
  2. Make sure that your local MySQL database is reachable from the internet, i.e. having the correct firewall/NAT settings in your router.
  3. Use your public IP address as $hostname in your code.