title: Mongoose: How to exclude virtual id field during populate
body: <p>I'm trying to exclude the virtual id field that Mongoose sets. </p>
  
  <pre><code>var Bar = new Schema({ body: String });    
  var Foo = new Schema({ bars: type: Schema.Types.ObjectId, ref: 'Bar' });
  
  Foo
  .find({..query...})
  .populate('bars', 'body -_id')
  .exec(function(err, foos){
     console.log(foos); // { bars: [{id: null, body: 'body string'}] }
  }); 
  </code></pre>
  
  <p>How do I get rid of that 'id' field? It's null anyway since I've excluded _id in populate?</p>