title: Append a Laravel collection with another collection
body: <p>I am trying to append an Eloquent collection with another Eloquent collection in Laravel 5.3. </p>
  
  <p>This is what I've done so far:  </p>
  
  <pre><code>$entries = Entry::all();
  $posts   = Post::all();
  
  $entries-&gt;merge($posts);
  </code></pre>
  
  <p>I tried to use <code>merge()</code> as shown in the code above, but it seems that I'm stuck with this kind of problem (since some of them have the same <code>id</code> with the same value):</p>
  
  <p><a href="https://laracasts.com/discuss/channels/general-discussion/laravel-42-collection-merge-eating-up-some-rows" rel="noreferrer">Collection merge eating up some rows</a></p>
  
  <p>Any ideas?</p>