Populate values from different Models - Mongoose/MongoDB Collections - NodeJS - node.js

Question

I have two main Schema in my project, Store, and User.
User collection as displayed in MongoDB Compass is the following :
_id : ObjectId("**5e830006c4cec2586875124b**")
hearts : Array
storeID : Array
email : "test#test.com"
name : "My name is Test"
photo : "fa75fa97-c5d8-4e63-a9ee-38441774a26e.jpeg"
slugAuthor : "my-name-is-test"
description : "My description is Test"
hash : "b841b82dcffdd0d517b5010d9ff2047ab447751a4e6dd573f9d55af..."
salt : "2bb0f785b134af11d7ca08d4086801fd880626498fbcf106c0df9a66"
__v : 0
Store collection as displayed in MongoDB Compass is the following :
_id : ObjectId("5e830050c4cec2586875124c")
tags : Array
name : "My activity is Test"
description : "My description us Test"
participants : 1
duree : 1
date : 2220-02-22T21:02:00.000+00:00
author : ObjectId("**5e830006c4cec2586875124b**")
created : 2020-03-31T08:33:20.234+00:00
slug : "my-activity-is-test"
__v : 0
What I need :
When I display the user information, I also want to search every Store he has created.
As you can see, the User id is found in the Store collection (author: ObjectId).
I need to display those information (User + list of stores that belongs to the User) when I hit the route http://..../store/my-name-is-test/5e830006c4cec2586875124b. In my route, I need to display as a slug the "slugAuthor" and the "author: ObjectId". (this is already managed).
What I have already tried (using .populate()) :
In my Store Schema :
author: {
type: mongoose.Schema.ObjectId,
ref: 'User',
}
In my User Schema :
listStores: [{
type: mongoose.Schema.ObjectId,
ref: 'Store'}],
In my controller:
exports.myProfil = async (req, res) => {
const user = await User.findOne({slugAuthor: req.params.slugAuthor}).populate('listStores')
res.render('my-profil', {user});
};
It gives me access to the following data :
{
"hearts": [],
"listStores": [],
"_id": "5e830006c4cec2586875124b",
"email": "test#test.com",
"name": "My name is Test",
"photo": "fa75fa97-c5d8-4e63-a9ee-38441774a26e.jpeg",
"slugAuthor": "my-name-is-test",
"description": "My description is Test",
"__v": 0
}
As you can see, "listStores" array is empty but I need it to be filled with every stores created by this user.
Would you please be kind enough to help me out here,
Many thanks

Answer 1

You can use aggregation for that. Take a look at the lookup
$lookup:
{
from: 'Store',
localField: _id, // the _id of the user
foreignField: author,
as: "listStores" // this might be something else
}
In this case instead of find you have to use User.aggregate
Hope this helps!