大神仙，老神仙，不大不小中神仙，给看看呗.为何继承了就没数据值了呢。小弟我啥没理解呢

<?php<br>
$config = array();<br>
$config['DB_HOST']='localhost';<br>
$config['DB_USER']='root';<br>
$config['DB_PASS']='';<br>
$config['DB_NAME']='hfdb';<br>
<br>
<br>
foreach($config as $name =>$val)<br>
{<br>
	define($name,$val);<br>
}<br>
$dsn = "mysql:host=".DB_HOST.";dbname=".DB_NAME;<br>
$dbo = new PDO($dsn,DB_USER,DB_PASS);<br>
<br>
/*<br>
<br>
$sql="select * from task";<br>
<br>
$stmt =$dbo->prepare($sql);<br>
<br>
$stmt ->execute();<br>
$results = $stmt -> fetchALL(PDO::FETCH_ASSOC);<br>
print_r($results); <br>
$stmt ->closeCursor();<br>
*/<br>
<br>
<br>
<br>
class DB_Connect{<br>
<br>
	public $db;<br>
	<br>
	<br>
	protected function __construct($dbo=NULL)<br>
	{<br>
<br>
			$dsn = "mysql:host=".DB_HOST.";dbname=".DB_NAME;<br>
			try<br>
			{<br>
			$this->db =new PDO($dsn,DB_USER,DB_PASS);<br>
			}<br>
			catch(Exception $e)<br>
			{<br>
				die($e->getMessage());<br>
			}<br>
	}<br>
}<br>
<br>
class Task extends DB_Connect<br>
{		<br>
	public function __construct($dbo=NULL,$useData=NULL)<br>
	{<br>
		parent::__construct($dbo);<br>
	}<br>
	<br>
	private function _LoadEventTask ($id=NULL)<br>
	{<br>
		$sql="SELECT * FROM `task`";<br>
<br>
		try<br>
		{<br>
			$stmt = $this->db->prepare($sql);<br>
			$stmt ->execute();<br>
			$results = $stmt -> fetchALL(PDO::FETCH_ASSOC);<br>
			$stmt ->closeCursor();<br>
			return $results;<br>
		}<br>
		catch( Exception $e)<br>
		{<br>
			die($e->getMessage() );<br>
		}<br>
	}<br>
}<br>
$ssss= new Task($dbo);<br>
var_dump ($ssss);