title: ManyToOne in a twig template
body: <p>I have the following tables (and entities in <a href="/questions/tagged/symfony2" class="post-tag" title="show questions tagged &#39;symfony2&#39;" rel="tag">symfony2</a> / <a href="/questions/tagged/doctrine2" class="post-tag" title="show questions tagged &#39;doctrine2&#39;" rel="tag">doctrine2</a>):</p>
  
  <pre><code>+------------------+                  +--------------------+
  |  forum_sections  |                  |  forum_categories  |
  +------------------+                  +--------------------+
  | id               ├--------|         | id                 |
  | title            |        |---------| section            |
  | position         |                  | position           |
  | created_at       |                  | title              |
  +------------------+                  | description        |
                                        +--------------------+
  </code></pre>
  
  <p>I want to archive the following html page (without the bullets ofcource):</p>
  
  <ul>
  <li>this is a title  (from forum_sections->title)
  
  <ul>
  <li>forum 1      (from forum_categories->title)</li>
  <li>forum 2      (from forum_categories->title)</li>
  </ul></li>
  <li>this is another title  (from forum_sections->title)
  
  <ul>
  <li>forum 3      (from forum_categories->title)</li>
  </ul></li>
  </ul>
  
  <p>I did some research on how to do this. So far I tried the following in my twig layout:</p>
  
  <pre><code>{% for section in sections %}
      &lt;h1&gt;title&lt;/h1&gt;
  
      {% for category in categories %}
          bla bla
      {% endfor %}
  {% endfor %}
  </code></pre>
  
  <p>Is this even possible with a 'findAll' query in Doctrine2? I tried some combinations, but they seem to get all the boards ignoring the sections.</p>