title: Remove id form embeded documents
body: <p>Hi i have embedded document like this:
  I want to remove  &quot;id_group&quot; of worker because its unnecessary and change format date to correct. I need agregate function to to this? What is easy way to do this?</p>
  <pre><code>{
      &quot;_id&quot;: {
          &quot;$oid&quot;: &quot;6242d36461e63768f0ac1529&quot;
      },
      &quot;id_z&quot;: 10,
      &quot;name&quot;: &quot;Journalists&quot;,
      &quot;addres&quot;: &quot;New York&quot;,
      &quot;workers&quot;: {
          &quot;worker&quot;: [{
              &quot;id_worker&quot;: 15,
              &quot;name&quot;: &quot;example&quot;,
              &quot;job&quot;: &quot;example&quot;,
              &quot;id_director&quot;: 25,
              &quot;hired&quot;: &quot;2005-02-20&quot;,
              &quot;id_group&quot;: 10
          }, {
              &quot;id_worker&quot;: 16,
              &quot;name&quot;: &quot;example&quot;,
              &quot;job&quot;: &quot;example&quot;,
              &quot;id_director&quot;: 26,
              &quot;hired&quot;: &quot;2005-02-20&quot;,
              &quot;id_group&quot;: 10
          }]
      }
  }
  
  </code></pre>