doctrine 一次insert 或者操作大量 record

http://docs.doctrine-project.org/projects/doctrine-orm/en/2.0.x/reference/batch-processing.html#batch-processing

我的例子：

     $cities=Array();
      $cities=Array();
     
     $em = $this->getDoctrine()->getEntityManager();
     
     $qb=$em->getRepository('AcmeBannieresBundle:TVille')->createQueryBuilder('tv');
     //$cities=$qb->getQuery()->execute();
     $iterableResult =$qb->getQuery()->iterate();
    
     $j=0;
     while (($row = $iterableResult->next()) !== false) {
         $city=$row[0];
         //$city=new TVille();
         for ($p=1;$p++;$p<9){
             $banner=new BannerCity();
             $banner->setCity($city);
             $banner->setPosition($p);
             //$city->addBannerCity($banner);    
             $em->persist($banner);
         }
         //$em->persist($city);
            $j++;
            if ($j>100){
                $em->flush();
                $em->clear(); // Detaches all objects from Doctrine!
                $j=0;
            }
           //$em->detach($city);
     }
    // $em->flush();
      
     return array();