Mongoose populate sub-sub document

Question

I have this setup in my MongoDB

Items:

title: String
comments: [] // of objectId\'s

Comments:

user: ObjectId()
item: Ob         


        

Answer 1

To add one final method that people may want to use to select only particular fields from sub-documents, you can use the following 'select' syntax:

  Model.findOne({ _id: 'example' })
    .populate({ 
      path: "comments", // 1st level subdoc (get comments)
      populate: { // 2nd level subdoc (get users in comments)
        path: "user",
        select: 'avatar name _id'// space separated (selected fields only)
      }
    })
    .exec((err, res) => { 
        // etc
     });