<?php

class DB
{
    static private $_instance;

    static private $_opts = array(
        PDO::ATTR_ERRMODE       => PDO::ERRMODE_EXCEPTION,
        PDO::ATTR_EMULATE_PREPARES  => true,
        PDO::MYSQL_ATTR_INIT_COMMAND    => 'set names utf8',
    );

    static private $_conn = array(
        'dsn'       => 'mysql:host=127.0.0.1;dbname=auto',
        'user'      => 'root',
        'passwd'    => 'root',
    );

    static public function getInstance()
    {
        self::$_instance OR self::$_instance = new self;
        return self::$_instance;
    }

    public function test()
    {
        foreach (self::$_instance->query('SELECT id FROM blog') as $post)
        {
            echo $post['id'] . "\t";
        }
    }

    private function __construct()
    {
        try
        {
            self::$_instance = new PDO(self::$_conn['dsn'],
                           self::$_conn['user'],
                           self::$_conn['passwd'],
                           self::$_opts);
        }
        catch (PDOException $e)
        {
            echo 'DB connection error: ' . $e->getMessage();
            exit;
        }
    }
}

?>