Database connection/PDO in php

DBConfig.php

<?php
return array(
    'dbname'   => 'somedbname',
    'host'     => 'database',
    'username' => 'admin',
    'password' => 'admin',
);
?>

DBConnection.php

<?php
/*
 * Database connection
*/

class DB {

    private static $db = null;
    private $conn = NULL;

    private function __construct() {
        // Array with configuration values
        $dbConfig = require_once(realpath(dirname(__FILE__)) . "DBConfig.php");

        if(is_null($this->conn)){
            // No connection to video is made by yet. Let's make one
            $dsn = 'mysql:dbname=' . $dbConfig['dbname'] . ';host=' . $dbConfig['host'];

            try {
                $this->conn  = new PDO($dsn, $dbConfig['username'], $dbConfig['password']);
            } catch (PDOException $e) {
                // NOTE IKKE BRUK DETTE I PRODUKSJON
                print('Connection failed: ' . $e->getMessage());
            }
        }
    }

    /**
     *
     * @return Database connection for database / PDO object
     */
    public static function getDBConnection(){
        if (DB::$db==null) {
            DB::$db = new self();
        }
        return DB::$db->conn;
    }
}