php - join with JDatabase doesn't work -

i'm beginner joomla! , i'm trying informations database, doesn't work, joomla! display blank page, means there execution error php code.

here code of request :

$query ->select($db->quotename(array('orders.order_id', 'user.first_name', 'user.last_name'))) ->from($db->quotename('#__orders', 'orders')) ->join('left', $db->quotename('#__userinfos', 'user').' on ('.$db->quotename('orders.user_id').' = '.$db-quotename('user.user_id') .')') ->where($db->quotename('address_type').' = '.$db->quote('bt')); 

i know error comes join function, because when comment it, there no error

here sql request want call

select orders.order_id, users.first_name, users.last_name  prefix_orders orders left join prefix_userinfos users on orders.ser_id = users.user_id address_type = 'bt'"); 

thanks

you have syntax error in last quote of join method:

 $db-quotename('user.user_id') 

instead of

$db->quotename('user.user_id') 

illusive one, say.