Foreign key best practice

Hello there,
i’m new to both, mongo and meteor/node.js, so sry for this kind of stupid question - i’m trying to create a small blog for practice.
I already googled around bu found different solutions and wonder which one is the way to go.

I want to create categories(_id,…) and posts which belong to these categories.

  1. So the SQL way to do it would be posts(_id, category_id,…)
    ^^ i could find this kind of implementation in some meteor tutorials like here:
  2. But it seems like a lot of people instead use sth. like categories(_id,…,collection(posts))
    So which is the better way to go?

I tried to implement the first one but am struggeling with a rather simple task i think: getting the current categories id.

What i did is:

  1. showing a list with all categories

  2. following the route

    Router.route(’/categories/:_id’, {
    name: ‘app_view’,
    template: ‘app_view’,
    data: function(){
    var currentCategory = this.params._id;
    return Categories.findOne({ _id: currentCategory });
    \3. Displaying a form for posts

{{> quickForm collection=“Posts” id=“insertPostForm” type=“insert”}}

using the following schema:

Schemas.Posts = new SimpleSchema({
    category_id: {
        type: String,
        autoValue: function(){
            //return this._id;
        autoform: { type: "hidden", label: false }

How do i get the currently selected category _id here?

thx for any help,