如何使用數據庫控制的CMenu菜單

數據庫結構
CREATE TABLE IF NOT EXISTS `menu` (
`menu_id` int(11) NOT NULL auto_increment,
`name` varchar(255) NOT NULL,
`date_added` datetime NOT NULL,
`last_updated` datetime NOT NULL,
`status` enum('active','inactive') NOT NULL,
PRIMARY KEY (`menu_id`),
UNIQUE KEY `name_UNIQUE` (`name`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=1 ;

CREATE TABLE IF NOT EXISTS `menu_item` (
`item_id` int(11) NOT NULL auto_increment,
`parent_id` int(11) default NULL,
`menu_id` int(11) NOT NULL,
`label` varchar(255) NOT NULL,
`url` text NOT NULL,
`description` text NOT NULL,
`date_added` datetime NOT NULL,
`last_updated` datetime NOT NULL,
`sort_order` int(11) NOT NULL,
`status` enum('active','inactive') NOT NULL,
PRIMARY KEY (`item_id`),
KEY `fk_menu_item_menu1` (`menu_id`),
KEY `fk_menu_item_menu_item1` (`parent_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 AUTO_INCREMENT=1 ;

ALTER TABLE `menu_item`
ADD CONSTRAINT `fk_menu_item_menu1` FOREIGN KEY (`menu_id`) REFERENCES `menu` (`menu_id`) ON DELETE CASCADE ON UPDATE NO ACTION,
ADD CONSTRAINT `fk_menu_item_menu_item1` FOREIGN KEY (`parent_id`) REFERENCES `menu_item` (`item_id`) ON DELETE SET NULL ON UPDATE NO ACTION;
模型中用來檢索菜單項的方法
public function getItems($menu_id, $parent_id=null)
{
$results = Yii::app()->getDb()->createCommand();
$results->select('item_id, label, url')->from('{{menu_item}}');

if($parent_id === null)
$results->where('menu_id=:mid AND parent_id IS NULL', array(':mid'=>(int)$menu_id));
else
$results->where('menu_id=:mid AND parent_id=:pid', array(':mid'=>(int)$menu_id, ':pid'=>$parent_id));

$results->order('sort_order ASC, label ASC');
$results = $results->queryAll();

$items = array();

if(empty($results))
return $items;

foreach($results AS $result)
{
$childItems=$this->getItems($menu_id, $result['item_id']);
$items[] = array(
'label' => $result['label'],
'url' => $result['url'],
'itemOptions' => array('class'=>'listItem'),
'linkOptions' => array('class'=>'listItemLink', 'title'=>$result['label']),
'submenuOptions'=> array(),
'items' => $childItems,
);
}

return $items;
}
CMenu 初始化
//get the menu with id #2
$items=$this->getItems(2);
$menu = array(
'id' => 'nav',
'activeCssClass'=>'selected',
'linkLabelWrapper'=>null,
'htmlOptions'=>array('class'=>'topNav'),
'items'=>$items
);
$this->widget('zii.widgets.CMenu', $menu);