title: Querying a MongoDB based on Mongo ID in a node.js app
body: <p>I'm using a node.js and mongodb, and I'm trying to query the database based on the mongo generated ID using the following:</p>
  
  <pre><code>    collection.findOne( {_id:doc._id} , function(err, item) {});
  </code></pre>
  
  <p>I am 100% certain that my doc._id is an exact match to the doc _id that I am looking for in the collection, and yet I get a null response from the db query.</p>
  
  <p>I have tried this using other keys in the document and it returns the document just fine. It's only when I try to use the mongo ID.</p>