title: Embedded document without Array?
body: <p>I understand how to <a href="http://mongoosejs.com/docs/2.7.x/docs/embedded-documents.html">embed documents</a> in Mongoose, and they seem fairly straightforward if storing as arrays, for which the use case is fairly obvious: </p>
  
  <pre><code>var CommentSchema = new Mongoose.Schema({...});
  var BlogPostSchema = new Mongoose.Schema({
      comments : [CommentSchema],
  });
  </code></pre>
  
  <p>But, what I don't see how to do after looking over the documentation forward and backward, is how to store a single sub-document that doesn't need or want to be in an Array.  </p>
  
  <pre><code>var UserSchema = new Mongoose.Schema({...});
  var BlogPostSchema = new Mongoose.Schema({
      author: ??? // 'UserSchema' and UserSchema do not work here. 
  });
  </code></pre>
  
  <p>Is there any way to make this work?  I don't want to just store the ObjectId, but rather, store a complete copy of the User record, but don't need or want an array.  </p>