logikabisnis.md

punya satu kategori:

shoes = Category.create(name: "shoes")

terus ada beberapa produk yang dimasukkan ke kategori shoes:

sepatu_a = Product.create(name: "sepatu a")
sepatu_b = Product.create(name: "sepatu b")

sepatu_a.product_categories.create(category: shoes)
sepatu_b.product_categories.create(category: shoes)

sepatu_a.categories # => ...name: "shoes", ...
sepatu_b.categories # => ...name: "shoes", ...

nah sekarang gimana cara mencari semua produk yang berkategori shoes?

shoes.products # => ..., name: "sepatu a" .., ... name: "sepatu b", ...

model.rb

class Product < ActiveRecord::Base
	has_many :categories, through: :product_categories 
	has_many :product_categories
end

class ProductCategory < ActiveRecord::Base
	belongs_to :product
	belongs_to :category
end

class Category < ActiveRecord::Base
	has_many :products, through: :product_categories
	has_many :product_categories
end