A very simple Symfony controller demonstrating the use of the Doctrine ORM - http://www.symfonycentral.com

DefaultController.php

<?php

namespace MyCompany\BlogBundle\Controller;

use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\Template;

/* Note below: we NEEED to include the Entity class Doctrine built for us */
use MyCompany\BlogBundle\Entity\Post as Post;

class DefaultController extends Controller
{
    /**
     * @Route("/article/{id}", name="blog_view", requirements={"id" = "\d+"})
     * @Template()
     */
    public function indexAction($id)
    {
        /* We use the Doctrine Repository object to search the database */
        $post = $this->getDoctrine()
                ->getRepository('MyCompanyBlogBundle:Post')
                ->find($id);
	
        if (!$post) {
            return array('body' => '', 'title' => '');
        }
        
        /* If a matching post was found for the ID, use the entity object */
        return array(
            'body' => $post->getBody(), 
            'title' => $post->getTitle()
        );
    }


    /**
     * @Route("/article/add", requirements={"_method" = "GET"})
     * @Template()
     */
    public function addAction()
    {
    	return array();
    }


    /**
     * @Route("/article/add", requirements={"_method" = "POST"})
     * @Template()
     */
    public function saveAction()
    {
        $request = $this->getRequest();
        $title = $request->get('title');
        $body = $request->get('body');
        
        /* Construct the Entity using the values provided in the form */
        $post = new Post();
        $post->setTitle($title);
        $post->setBody($body);
    	
        /* We use the Doctrine "EntityManager" to persist objects */
        $em = $this->getDoctrine()->getEntityManager();
        $em->persist($post);
        $em->flush();
        /* The object isn't saved UNTIL we call ->flush... */
        
        return $this->redirect($this->generateUrl('blog_view', array('id' => $post->getId())));
    }
}