title: Eager loading without empty collections
body: <pre><code>$products = Product::with(
      array(
          'productDescriptions' =&gt; function($query) {
               $query-&gt;lang(App::getLocale());
           },
          'productImages' =&gt; function($query) {
               $query-&gt;imageType('thumbnail');    
          }))
      -&gt;paginate($items_per_page);
  </code></pre>
  
  <p>Hi, is there an easy way to eager load relationships but only if they exists? More specifically I would like to get only these products, if their productDescriptions are not empty.
  In SQL I would simply do a inner join, but how to do it an easy way in Eloquent? I could foreach over all returned products and check if <code>$product-&gt;productDescription-&gt;count() &gt; 0</code> but maybe there is simpler way to achieve that.</p>