title: how to delete document from collection in mongodb?
body: <p>I have id printing in controller from client  now i want to delete this document from mongodb with below code is not showing any error but not even deleting document from collection , How can i delete document using <code>_id</code> ?</p>
  
  <p>controller.js</p>
  
  <pre><code>var Diagram = {
      remove: function(id, res) {
          console.log('deletecontroller', id);
          diagram.remove({
              _id: id
          });
      }
  }
  module.exports = Diagram;
  </code></pre>