[PHP] Call to a member function prepare() on a non-object Opcje

[troian]

Tak jak w tytule tematu, skrypt zwraca mi błąd:

Kod

Fatal error: Call to a member function prepare() on a non-object in include.db.php on line 33

[PHP] pobierz, plaintext 
class db
{
	protected static $host;
	protected static $port;
	protected static $user;
	protected static $pass;
	private static $pdo;
 
	public function __construct()
	{
		self::$host = HOST;
		self::$port = PORT;
		self::$user = USER;
		self::$pass = PASS;
		$options  = array(
            PDO::MYSQL_ATTR_INIT_COMMAND => 'SET NAMES UTF8'
        );
        try 
		{
            self::$pdo = new PDO("mysql:host={self::$host};port={self::$port}", self::$user, self::$pass, $options);
			self::$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
		} 	
		catch(PDOException $error) 
		{
            die("ERROR CONNECT: " .  $error->getMessage());
        }
	}
 
	public static function query($query='',$value=array(),$type="true") 
	{
		try 
		{
			$query = self::$pdo->prepare($query);
			switch($type)
			{
				case 'true':
				case 'false':
					$tab = array('true' => array(0 =>'true',1=>'false'),'false' => array(0 =>'false',1=>'true'));
					$result = $query->execute($value) ? $tab[$type][0] : $tab[$type][1];					
					break;
				default:
					$result = $query->execute($value) ? $query->$type() : false;
			}
		} 
		catch(PDOException $error) 
		{ 
			die("ERROR QUERY: " . $error->getMessage()); 
		}
 
		return $result;
	}	
}
 
[PHP] pobierz, plaintext 

dokładnie chodzi o tą oto linijkę

Kod

$query = self::$pdo->prepare($query);

[troian]

to w jaki sposób wywołać obiekt pdo ? $this->pdo nie działa