Mongoose Virtuals in MongoDB Aggregate

Question

My Mongoose Schema is as follows:

var DSchema = new mongoose.Schema({
  original_y: {type: Number},,
  new_y: {type: Number},,
  date: {type: Date},
  dummy         


        

Answer 1

A couple notes in the docs touch on why this is so:

• Arguments are not cast to the model's schema because $project operators allow redefining the "shape" of the documents at any stage of the pipeline, which may leave documents in an incompatible format.
• The documents returned are plain javascript objects, not mongoose documents (since any shape of document can be returned).

But it goes beyond this because the aggregate operation is performed server-side, where any client-side Mongoose concepts like virtuals do not exist.

The result is that you'll need to include the date field in your $project and $group stages and add your own dateformatted field to the results in code based on the date values.