Article.php

<?php

namespace AppBundle\Entity;

use Doctrine\ORM\Mapping as ORM;

/**
 * Article
 *
 * @ORM\Table(name="article")
 * @ORM\Entity(repositoryClass="AppBundle\Repository\ArticleRepository")
 */
class Article
{
    /**
     * @var int
     *
     * @ORM\Column(name="id", type="integer")
     * @ORM\Id
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    private $id;

    /**
     * @var string
     *
     * @ORM\Column(name="title", type="string", length=255)
     */
    private $title;

    /**
     * @var string
     *
     * @ORM\Column(name="description", type="text")
     */
    private $description;

    /**
     * @var Author
     *
     * @ORM\ManyToOne(targetEntity="AppBundle\Entity\Author", inversedBy="articles")
     */
    private $author;

    /**
     * Get id
     *
     * @return int
     */
    public function getId()
    {
        return $this->id;
    }

    /**
     * Set title
     *
     * @param string $title
     *
     * @return Article
     */
    public function setTitle($title)
    {
        $this->title = $title;

        return $this;
    }

    /**
     * Get title
     *
     * @return string
     */
    public function getTitle()
    {
        return $this->title;
    }

    /**
     * Set description
     *
     * @param string $description
     *
     * @return Article
     */
    public function setDescription($description)
    {
        $this->description = $description;

        return $this;
    }

    /**
     * Get description
     *
     * @return string
     */
    public function getDescription()
    {
        return $this->description;
    }

    /**
     * Set author
     *
     * @param \AppBundle\Entity\Author $author
     *
     * @return Article
     */
    public function setAuthor(\AppBundle\Entity\Author $author = null)
    {
        $this->author = $author;

        return $this;
    }

    /**
     * Get author
     *
     * @return \AppBundle\Entity\Author
     */
    public function getAuthor()
    {
        return $this->author;
    }
}

ArticleRepository.php

<?php

namespace AppBundle\Repository;

/**
 * ArticleRepository
 *
 * This class was generated by the Doctrine ORM. Add your own custom
 * repository methods below.
 */
class ArticleRepository extends \Doctrine\ORM\EntityRepository
{
    public function getArticles()
    {
        return $this->createQueryBuilder('a')
            ->join('a.author', 'au')
            ->getQuery()
            ->getResult();
    }
}

Author.php

<?php

namespace AppBundle\Entity;

use Doctrine\Common\Collections\Collection;
use Doctrine\ORM\Mapping as ORM;

/**
 * Author
 *
 * @ORM\Table(name="author")
 * @ORM\Entity(repositoryClass="AppBundle\Repository\AuthorRepository")
 */
class Author
{
    /**
     * @var int
     *
     * @ORM\Column(name="id", type="integer")
     * @ORM\Id
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    private $id;

    /**
     * @var string
     *
     * @ORM\Column(name="name", type="string", length=255)
     */
    private $name;

    /**
     * @var string
     *
     * @ORM\Column(name="surname", type="string", length=255)
     */
    private $surname;

    /**
     * @var Collection
     *
     * @ORM\OneToMany(targetEntity="AppBundle\Entity\Article", mappedBy="author")
     */
    private $articles;

    /**
     * Get id
     *
     * @return int
     */
    public function getId()
    {
        return $this->id;
    }

    /**
     * Set name
     *
     * @param string $name
     *
     * @return Author
     */
    public function setName($name)
    {
        $this->name = $name;

        return $this;
    }

    /**
     * Get name
     *
     * @return string
     */
    public function getName()
    {
        return $this->name;
    }

    /**
     * Set surname
     *
     * @param string $surname
     *
     * @return Author
     */
    public function setSurname($surname)
    {
        $this->surname = $surname;

        return $this;
    }

    /**
     * Get surname
     *
     * @return string
     */
    public function getSurname()
    {
        return $this->surname;
    }
    /**
     * Constructor
     */
    public function __construct()
    {
        $this->articles = new \Doctrine\Common\Collections\ArrayCollection();
    }

    /**
     * Add article
     *
     * @param \AppBundle\Entity\Article $article
     *
     * @return Author
     */
    public function addArticle(\AppBundle\Entity\Article $article)
    {
        $this->articles[] = $article;

        return $this;
    }

    /**
     * Remove article
     *
     * @param \AppBundle\Entity\Article $article
     */
    public function removeArticle(\AppBundle\Entity\Article $article)
    {
        $this->articles->removeElement($article);
    }

    /**
     * Get articles
     *
     * @return \Doctrine\Common\Collections\Collection
     */
    public function getArticles()
    {
        return $this->articles;
    }
}

DefaultController.php

<?php

namespace AppBundle\Controller;

use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route;
use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Symfony\Component\HttpFoundation\Request;

class DefaultController extends Controller
{
    /**
     * @Route("/", name="homepage")
     */
    public function indexAction(Request $request)
    {
        $articles = $this->getDoctrine()->getRepository('AppBundle:Article')->getArticles();

        dump($articles);
        // replace this example code with whatever you need
        return $this->render('default/index.html.twig', array(
            'base_dir' => realpath($this->container->getParameter('kernel.root_dir').'/..'),
        ));
    }
}