thinkphp3.1视图模型生成的SQL语句执行不了,该怎么处理

//订单视图

Class OrderViewModel extends ViewModel{
	public $viewFields = array(
		'order' => array('id','orderNo','date','money','memo','state','_type'=>'LEFT'),
		'client' => array('clientName','_on'=>'order.client_id=client.id','_type'=>'RIGHT'),
		'user' => array('userName','_on'=>'order.user_id=user.id'), 
	);
	
}
?>

$Model = D("OrderView");
		$result = $Model->select();
		p($result);die;

SELECT order.id AS id,order.orderNo AS orderNo,order.date AS date,order.money AS money,order.memo AS memo,order.state AS state,client.clientName AS clientName,user.userName AS userName FROM or_order order LEFT JOIN or_client client ON order.client_id=client.id RIGHT JOIN or_user user ON order.user_id=user.id