Question

Let’s say customer is adding multiple products to cart.
Add car, apartment, tour, some coupons.
Products belong to categories.
Category has name attribute.
But how to give different attributes to car, apartment, tour, coupon?
I can’t definitely create everything from product model.
So should I create different models for each category and connect through has many ro products model?
Or am I going to wrong direction?
Thanks

Answer 1

Having a Category for individual product seems to be a good approach here. Since your Category differs according to attributes. What you can do is create One more model, let’s say: MasterCategory which has many Category and Category belongs to MasterCategory, which means for your MasterCategory Cars you’ll have Audi, BMW, Nissan etc etc. categories and then link your products to their respective vendors in a table products_categories which will have product_id, category_id.

In my opinion, schema could go like this:

ProductsCategory:
product_id, category_id

MasterCategory:
id, name, created_at, updated_at

Category:
id, master_category_id, parent_id, name, position, name, permalink

For e.g. – A car MasterCategory will look like this:

#<MasterCategory id: 1, name: "cars", created_at: "2012-02-14 13:03:45", updated_at: "2012-02-14 13:03:45">

and its categories will be:

[#<Category id: 1, master_category_id: 1, parent_id: nil, position: 0, name: "cars", created_at: "2012-02-14 13:03:45", updated_at: "2012-02-14 13:03:45", permalink: "cars">, #<Category id: 2, master_category_id: 1, parent_id: 1, position: 0, name: "Audi", created_at: "2012-02-14 13:03:45", updated_at: "2012-02-14 13:32:51", permalink: "cars/audi">]

Now you can have two methods parent and children in your Category Model using parent_id attribute to locate and traverse master and sub categories easily. And you can use permalink attribute to easily locate a category which is under another category with one query: Category.find_by_permalink(params[:permalink]) and can display all the products related with this particular category. In future when you’ll scale, I can bet you, you’ll require this position attribute to manage position of your categories to display on your page. And in last master_category_id will give you an ease in life with:

car = MasterCategory.find(1)
car.categories.where("parent_id IS NOT NULL")

All the best!! 🙂