从joomla 2.5中的数据库检索数据

我有两张桌子：

• agahi：（agahi_id，ostan，car_id，published）

• 用户_agahi（用户_agahi，奥斯坦，塔拉菲阿加希用户，已发布）

我使用下面的代码，但我无法检索数据

class modostanHelper
{

          public function retrieve()
          {
              $db=JFactory::getDBo();
            $sql="create view agahi as(select ostan,count(id_useragahi) as text_agahi from #__npco_useragahi where published=1 group by ostan) ";

              $db->setQuery($sql);

                           $db=JFactory::getDBo();
              $sql_1="create view useragahi AS (select ostan,count(id_agahi) as text_useragahi from #__npco_agahi where published=1 group by ostan) ";
              $db->setQuery($sql_1);

                          $db=JFactory::getDBo();
                     $sql_2="select * from agahi,useragahi where agahi.ostan=useragahi.ostan";
                         $db->setQuery($sql_2);                          
                return $db->loadAssocList();


            }
}

在文件

default.php

中，我使用下面的代码

之后

$db=JFactory::getDBo();


        $sql="create view agahi as(select ostan,count(id_useragahi) as text_agahi from #__npco_useragahi where published=1 group by ostan) ";

          $db->setQuery($sql);

执行查询：

$db->query()