How to display a menu in an online store?

Question

MongoDB

Hello!
I am writing a bicycle (online store) for myself on node.js and mongodb (mongoose).
But there was a question on operation with a tree of categories.
Now there is a structure like this:

var CategorySchema = new Schema({
    name: String,
    slug: String,
    text: String,
    parentSlug: {type: String, default: ""},
    ancestry: {type:[String], default: []} // предки для получения полного урла категории и хлебных крошек
});

nesting will be 4-5 maximum.
Task: displaying the menu as on kosi-pili.ru (the menu itself is the 1st level of nesting, and when you hover over the mouse, 2 and 3 are displayed).
What is the best way to do this?
The disadvantage of this structure is that to collect the tree, recursion to the database is required, which is not suitable (the number of all sections is about 300 - a very large overhead). Yes, and asynchronous recursion is still fun ...

Answer 1

to collect the tree, recursion to the base is required

Keep a list of (all) ancestors in children, then no recursions are needed.