query uitvoeren met PDO

<?php
class database extends PDO {

function __construct($dblogin) 
  {
    try 
    {
      parent::__construct('mysql:host=127.0.0.1;dbname='.$dblogin['db'], $dblogin['user'], $dblogin['pass']);
      $this->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    }
    catch (PDOException $e) 
    {
      if ($this->debug) echo $e->getMessage();
    }
  }


  function query($sql, $params = NULL)
  {   
    $starttime = microtime(TRUE);
    try 
    {
      if (is_null($params))
      {
        $results = parent::query($sql);
      }
      else
      {
        $stmt = parent::prepare($sql);
        foreach ($params as $key => $value)
        {
          if (is_int($value))
            $stmt->bindParam($key, $value, PDO::PARAM_INT);
          else if (is_string($value))
            $stmt->bindParam($key, $value, PDO::PARAM_STR);
          else if (is_bool($value))
            $stmt->bindParam($key, $value, PDO::PARAM_BOOL);
          else
            $stmt->bindParam($key, $value, PDO::PARAM_NULL);
        }
        $stmt->execute();
        $results = $stmt->fetchAll();
      }
    }
    catch (PDOException $e) 
    {
      if ($this->debug) echo $e->getMessage();
    }
    $this->log[] = array('sql'=>$sql,'time'=>microtime(TRUE)-$starttime);
    return (isset($results)) ? $results : NULL;
  }

}
?>

<?php
$dblogin = array(
    'host' => 'mijnhost',
    'db' => 'mijndb',
    'user' => 'user',
    'pass' => 'pass',
);

include ('class.database.php');
$database = new database($dblogin);
$sql = "SELECT * FROM contacts ORDER BY id";
$contacts = $database->query($sql);

print_r ($contacts);
?>