title: How to use mongoose findOne
body: <p>I have the below schema (apologies that it is in coffeescript)</p>
  
  <pre><code>Schema = mongoose.Schema
  
  AuthS = new Schema
      auth:   {type: String, unique: true}
      nick:   String
      time:   Date
  Auth = mongoose.model 'Auth', AuthS
  </code></pre>
  
  <p>I simply want to recover one record which is definitely in my database:</p>
  
  <pre><code>Auth.findOne({nick: 'noname'}, function(obj) { console.log(obj); });
  </code></pre>
  
  <p>Unfortunately this always logs <code>null</code>. <code>db.auths.findOne({nick: 'noname'})</code> in mongo shell always returns a value. What is going on? </p>