title: Mongodb $push in nested array
body: <p>I want add new data my nested array</p>
  
  <p>My document is:</p>
  
  <pre class="lang-json prettyprint-override"><code>{
    "username": "erkin",
    "email": "erkin-07@hotmail.com",
    "password": "b",
    "playlists": [
      {
        "_id": 58,
        "name": "asdsa",
        "date": "09-01-15",
        "musics": [
          {
            "name": "INNA - Cola Song (feat. J Balvin)",
            "duration": "3.00"
          },
          {
            "name": "blabla",
            "duration": "3.00"
          }
        ]
      }
    ]
  }
  </code></pre>
  
  <p>I want add music in this playlist section:</p>
  
  <pre class="lang-json prettyprint-override"><code>{
    "username": "erkin",
    "email": "erkin-07@hotmail.com",
    "password": "b",
    "playlists": [
      {
        "_id": 58,
        "name": "asdsa",
        "date": "09-01-15",
        "musics": [
          {
            "name": "INNA - Cola Song (feat. J Balvin)",
            "duration": "3.00"
          },
          {
            "name": "blabla",
            "duration": "3.00"
          },
          {
            "name": "new",
            "duration": "3.00"
          }
        ]
      }
    ]
  }
  </code></pre>
  
  <p>Here is what I tried:</p>
  
  <pre class="lang-php prettyprint-override"><code>$users-&gt;update(
    array(
      '_id' =&gt; new MongoId (Session::get('id')),
      'playlists._id' =&gt; $playlistId
    ),
    array(
      '$push' =&gt; array('playlists.musics' =&gt; array(
        'name' =&gt; 'newrecord',
        'duration' =&gt; '3.00'
      ))
    )
  );
  </code></pre>