title: Doctrine makes many queries for one-to-many relationship
body: <p>I have a Symfony2 app with Doctrine as ORM. In my app i have two entities with one-to-many relations. The one entity is <code>User</code> and the many entity is <code>Item</code>. Their relation config goes below:</p>
  
  <p>User:</p>
  
  <pre><code>oneToMany:
              items:
                  targetEntity: App\Bundle\ItemBundle\Entity\Item
                  fetch: EAGER
                  mappedBy: user
  </code></pre>
  
  <p>Item:</p>
  
  <pre><code>manyToOne:
          user:
              targetEntity: App\Bundle\UserBundle\Entity\User
              fetch: EAGER
              inversedBy: items
              joinColumn:
                  name: user_id
                  referencedColumnName: id
  </code></pre>
  
  <p>The problem is when i'm trying to get the list of <code>Users</code> and their <code>Items</code>, Doctrine creates separate query for each user to fetch it's items.</p>
  
  <p>The query itself is quite simple:</p>
  
  <pre><code>    $entities = $em-&gt;getRepository('AppUserBundle:User')-&gt;findBy([], [], 30);
  </code></pre>
  
  <p>Is it possible to fetch all related items for users in one query automatically using Doctrine?</p>
  
  <p>I'm using SF 2.7.6 and doctrine libs with versions:</p>
  
  <pre><code>doctrine/annotations                 v1.2.7  Docblock Annotations Parser
  doctrine/cache                       v1.5.1  Caching library offering an ob...
  doctrine/collections                 v1.3.0  Collections Abstraction library
  doctrine/common                      v2.5.1  Common Library for Doctrine pr...
  doctrine/dbal                        v2.5.2  Database Abstraction Layer
  doctrine/doctrine-bundle             1.6.0   Symfony DoctrineBundle
  doctrine/doctrine-cache-bundle       1.2.1   Symfony Bundle for Doctrine Cache
  doctrine/doctrine-migrations-bundle  1.1.1   Symfony DoctrineMigrationsBundle
  doctrine/inflector                   v1.0.1  Common String Manipulations wi...
  doctrine/instantiator                1.0.5   A small, lightweight utility t...
  doctrine/lexer                       v1.0.1  Base library for a lexer that ...
  doctrine/migrations                  v1.1.0  Database Schema migrations usi...
  doctrine/orm                         v2.5.1  Object-Relational-Mapper for PHP
  </code></pre>