Question

I have a Store that has many Catalogs and in turn each catalog has many Products.

The Product and Catalog shares many to many relationship.
One product can belong to many catalogs and vice-verse.

So, my model definition goes like this:

class Store < ActiveRecord::Base
   has_many :store_catalogs
   has_many :catalogs, :through => :store_catalogs
end

class StoreCatalog < ActiveRecord::Base
  belongs_to :store
  belongs_to :catalog
end

class Catalog < ActiveRecord::Base
    has_many :store_catalogs
    has_many :stores, :through => :store_catalogs
    has_and_belongs_to_many :product_set, :class_name => "Product"
 end    

class Product < ActiveRecord::Base
   has_and_belongs_to_many :catalogs
end

Now, I would like to access all the products that belongs to a store.
How do I link those together so that I get that? please suggest.

I am trying out various combinations from the rails console to pull the data, not sure if the console itself limits the relation based querying by any chance(though i would like to believe it doesn’t).

Answer 1

I think this should solve your problem

class Store < ActiveRecord::Base
  has_many :catalogs
  has_many :products, :through => :catalogs
end

class Catalog < ActiveRecord::Base
  belongs_to :store
  has_and_belongs_to_many :products
end

class Product < ActiveRecord::Base
  has_and_belongs_to_many :catalogs
end

And then you just need a table in your database called catalogs_products with catalog_id and product_id to link the has_and_belongs_to_many association.

Then in order to get all the products from a store just do

Store.find(id).products