One-To-Many relation in MongoDB - node.js

Question

At the moment I am looking at mongoDB. I try to implement a simple one-to-many relation using nodejs and mongoose:
Model/Schema User:
var mongoose = require('mongoose'),
Schema = mongoose.Schema;
var UserSchema = new Schema({
name: String
});
module.exports = mongoose.model('User', UserSchema);
Model/Schema Article:
var mongoose = require('mongoose'),
Schema = mongoose.Schema;
var ArticleSchema = new Schema({
name: {
type: String,
required: true
},
user: {
type: Schema.ObjectId,
ref: 'User'
}
});
module.exports = mongoose.model('Article', ArticleSchema);
So my question, now:
How can I get all Users including its Articles?
Do I really have to add a ref to my UserScheme, too? What is the best-practice in an one-to-many relation like this? Is there something like a join in mongodb?
One User has many Articles - an Article belongs to one User.
Calling something like /user/:user_id , I want to receive the user with _id=user_id containing all of his articles.

Answer 1

That is the most horrible idea, for various reasons.
First, there is a 16MB BSON document size limit. You simply can not put more into a document. Embedding documents is rather suited for "One-to-(VERY-)Few" relationships than for a "One-to-Many".
As for the use case: What is your question here? It is
For a given user, what are the articles?
REST wise, you should only return the articles when /users/:id/articles is GETed and the articles (and only the articles) should be returned as a JSON array.
So, your model seems to be natural. As for the user:
{
_id: theObjectId,
username: someString
…
}
and an article should look like this:
{
_id: articleIdOrSlugOrWhatever,
authors: [theObjectId],
// or author: theObjectId
retention: someISODate,
published: someOtherISODate
}
So when your REST service is called for /users/:id you'd simply look up
var user = db.users.findOne({_id:id})
And when /users/:id/articles is called, you'd lookup
var articles = db.articles.find({author:id})
Problem solved in a scalable way, adhering to REST principles.