PHP Connection Database MySQL Library

<?php
	#set your database authentication here
	define('dbname','<your database name>');
	define('user','<your username database>');
	define('pass','<your password database>');
	##Example
	// define('dbname','anonsec');
	// define('user','database');
	// define('pass','root');


	//How to use ?
	// # Script #
	// $con = Connection::getInstance();
	// # Your can execute your query using database connection from $con variable
	// 
	//
	// Connection::getInstance();
	// $nil= Connection::$con->prepare("select * from users");
	// if($nil->execute()){
	// 	echo "OK";
	// }
	///////////////////
	class Connection {

		private static $instance = null;
		public static function getInstance(){
			if ( self::$instance == null ){
				self::$instance = new Connection();
			}
			return self::$instance;
		}
		public static $con;
		public function __construct(){
			self::$con = new PDO("mysql:host=localhost;dbname=".dbname,user,pass);
			return self::$con;
		}

	}


?>