How can I include data from another collection in my mongoose object? - angularjs

Question

I am building an app with mongoDB and NodeJS with an Angular front end. I currently have users creating listings and then other users responding with bids within those listings, but want to include data of those responders. I am having a hard time including that user data in the bid create function and not sure why its not pulling.
Here is the listing schema
var mongoose = require("mongoose");
var Schema = mongoose.Schema;
var Bid = require('./bid');
var ListingSchema = new Schema({
topic: String,
description: String,
budget: String,
location: String,
req1: String,
req2: String,
req3: String,
created: String,
dateReq: String,
uid: String,
bids: [Bid.schema]
})
This is how I currently create new listings
function create(req, res) {
db.User.findById(req.user, function (err, user) {
if (err) {console.log(err);}
var newListing = new db.Listing(req.body);
newListing.uid = user._id
newListing.save(function (err, savedListing) {
if (err) {
res.status(500).json({ error: err.message });
} else {
user.listings.push(newListing);
user.save();
res.json(savedListing);
}
});
});
};
This is for new bids. For some reason, the db.User information is not getting pulled and my console log shows a blank object. (Yes I commented it out)
function create(req, res) {
// db.User.findById(req.user, function (err, user) {
// console.log(req.user);
// if (err) {console.log(err);}
db.Listing.findById(req.params.listingId, function(err, foundListing) {
var newBid = new db.Bid(req.body); // add data validation later
// newBid.uid = user._id
foundListing.bids.push(newBid);
foundListing.save(function(err, savedBid) {
res.json(newBid);
});
});
});
};

Answer 1

try using user_id as a Object reference and populate it when needed your schema should be somewhat like this
var ListingSchema = new Schema({ topic: String,description: String, budget: String, location: String, req1: String, req2: String, req3: String, created: String, dateReq: String,//THIS CREATES A REFERENCE TO THE SCHEMA USER AND TO USE THIS YOU CAN POPULATE IT.. uid: {type:Schema.type.ObjectId,ref:User}, bids: [Bid.schema]})