title: mongodb get _id as string in find query
body: <p>Here I have created a collection with a single document</p>
  
  <pre><code>db.getCollection('example').insert({"example":1});
  </code></pre>
  
  <p>I have tried to use Projection, and I get back the _id.</p>
  
  <pre><code>db.getCollection('example').find({"example":1},{"_id":1});
  
  {
      "_id" : ObjectId("562a6300bbc948a4315f3abc")
  }
  </code></pre>
  
  <p>However, I need the below output as shown below.</p>
  
  <ol>
  <li>id and not _id</li>
  <li><p>ObjectId("562a6300bbc948a4315f3abc") vs "562a6300bbc948a4315f3abc"</p>
  
  <p><code>{
      "id" : "562a6300bbc948a4315f3abc"
  }</code></p></li>
  </ol>
  
  <p>Although I can process #1 and #2 on my app server(PHP based) to get the desired ouput, I am looking if there is a way to get the expected result on querying from mongo itself</p>