Mam problem ze zrobieniem linków w mapie strony, mam taką tabelę:

[SQL] pobierz, plaintext 
CREATE TABLE `strony` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `tytul` varchar(250) collate utf8_unicode_ci NOT NULL,
  `link` varchar(250) collate utf8_unicode_ci NOT NULL,
  `tresc` longtext collate utf8_unicode_ci,
  `parent_id` bigint(20) DEFAULT NULL,
  `sortorder` bigint(20) DEFAULT NULL,
  `created_at` datetime NOT NULL,
  `updated_at` datetime NOT NULL,
  PRIMARY KEY  (`id`),
  KEY `parent_id_idx` (`parent_id`)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci AUTO_INCREMENT=17 ;
 
--
-- Zrzut danych tabeli `strony`
--
 
INSERT INTO `strony` (`id`, `tytul`, `link`, `tresc`, `parent_id`, `sortorder`, `created_at`, `updated_at`) VALUES
(1, 'aaa', 'aaa', NULL, NULL, 0, '2010-04-17 14:29:46', '2010-04-17 14:29:46'),
(2, 'bbb', 'bbb', NULL, NULL, 1, '2010-04-17 14:29:46', '2010-04-17 14:29:46'),
(3, 'ccc', 'ccc', NULL, NULL, 6, '2010-04-17 14:29:46', '2010-04-17 14:29:46'),
(4, 'ddd', 'ddd', '', 3, 0, '2010-04-17 14:29:46', '2010-04-17 14:45:39'),
(5, 'eee', 'eee', NULL, 3, 1, '2010-04-17 14:29:46', '2010-04-17 14:29:46'),
(8, 'fff', 'fff', NULL, NULL, 7, '2010-04-17 14:29:46', '2010-04-17 14:29:46'),
(9, 'ggg', 'ggg', NULL, NULL, 3, '2010-04-17 14:29:46', '2010-04-17 14:29:46'),
(10, 'hhh', 'hhh', NULL, NULL, 4, '2010-04-17 14:29:46', '2010-04-17 14:29:46'),
(11, 'iii', 'iii', NULL, 10, 0, '2010-04-17 14:29:46', '2010-04-17 14:29:46'),
(12, 'jjj', 'jjj', NULL, 10, 1, '2010-04-17 14:29:46', '2010-04-17 14:29:46'),
(13, 'kkk', 'kkk', NULL, 10, 2, '2010-04-17 14:29:46', '2010-04-17 14:29:46'),
(14, 'lll', 'lll', 'aaa', 4, 0, '0000-00-00 00:00:00', '0000-00-00 00:00:00'),
(15, 'mmm', 'mmm', 'bbb', 5, 0, '0000-00-00 00:00:00', '0000-00-00 00:00:00'),
(16, 'nnn', 'nnn', 'ccc', 15, 0, '0000-00-00 00:00:00', '0000-00-00 00:00:00');
 
--
-- Ograniczenia dla zrzutów tabel
--
 
--
-- Ograniczenia dla tabeli `strony`
--
ALTER TABLE `strony`
  ADD CONSTRAINT `strony_parent_id_strony_id` FOREIGN KEY (`parent_id`) REFERENCES `strony` (`id`);
[SQL] pobierz, plaintext 

I kod PHP:

[PHP] pobierz, plaintext 
$polaczenie=mysql_connect ("localhost", "root", "");
mysql_select_db ("baza");
mysql_query("SET NAMES utf8");
 
 
class Map
{
  private $menu;
  private $menu_link;
 
  public function tree_menu($index)
  {
  	$query = mysql_query ("SELECT *, IFNULL(parent_id, 0) AS parent FROM Strony HAVING parent = $index ORDER BY sortorder");
 
	$this->menu.= '<ul>';
	while ($x = mysql_fetch_assoc($query))
    {
        $this->menu.= '<li>';
 
		if($x['parent_id'] == null) $this->menu_link = null;
		$this->menu_link = $this->menu_link.'/'.$x['link'];
 
		$this->menu.= "<a href='".$this->menu_link."'>".$x['tytul']."</a>";	
        $this->tree_menu($x['id']);
        $this->menu.= '</li>';
    }
    $this->menu.= '</ul>';    
  }     
 
  public function showMap()
  {
  	echo $this->menu;
  }
}
 
 
 
$map = new Map();
$map->tree_menu(0);
$map->showMap();
[PHP] pobierz, plaintext 

Tworzy mi to poprawne drzewko mapy strony:



Ale linki są błędne, np. jak jest gałąź: ccc-eee-mmm-nnn to link powinien być postaci:
ccc/eee/mmm/nnn
a teraz mam:
ccc/ddd/lll/eee/mmm/nnn

Nie wiem już jak to zrobić żeby mi tworzyło poprawne linki, może macie jakiś pomysł ?