Rails user profile devise :has_many or :has_many_through relationships

Question

I'm wracking my brain about how to start setting up the following set of model relationships in my project. I'm not looking for the complete solution (models, tables, migrations, etc), just a little help to get me going in the right direction. I learn more by struggling on my own :)

In short, I want my Users (created with Devise) to have a set of Inclinations that represent preferences they have to certain things (i.e. warmer weather vs colder weather, watching sports vs playing sports, etc) on a sliding scale (coded 5 to -5, zero excluded). Each Inclination (or InclinationData?) will be in a separate table with a name, description, etc, and all Inclinations will get their data pulled from that table (so I don't repeat myself throughout my application). Also, every User will have one Inclination record for each InclinationData(?) by default.

As for the setup, will I need:

• 5 tables (3 main ones and two join tables)?
• Just three (main three models)?
• Four (main three models & a joining table for Inclinations and InclinationData)?
• Four (main three models & a joining table for Users & Inclinations)?
• Perhaps something simpler like a single Profile or Preferences model that's bound to a User?

I can never figure out how to decide if joining tables are necessary, and this is the most complex association I've ever tried.

I appreciate any help, and please let me know if you need more information to be able to help me out.

Answer 1

I think I've reasoned through your request:

Users has_many UserInclinations and Inclinations has_one UserInclinations. Roughly, the models should look like this:

class User < ActiveRecord::Base
  has_many :user_inclinations

  #default Devise attr_accessible
end

class UserInclinations < ActiveRecord::Base
  belongs_to :users
  belongs_to :inclinations

  attr_accessible :user_id, :inclination_id, preference_score
end

class Inclination < ActiveRecord::Base
  has_one :user_inclination

  attr_accessible :preference
end

Answer 2

You say, all Users have the same set of Inclinations. You can put the description of the Inclinations in one model/table and the users ratings in the joining table UserInclination , according to eabraham:

class User < ActiveRecord::Base
  has_many :users_inclinations
  has_many :inclinations, through: :users_inclinations

end

class UsersInclination < ActiveRecord::Base
  belongs_to :users
  belongs_to :inclinations

  attr_accessible :user_id, :inclination_id, preference_score
end

class Inclination < ActiveRecord::Base
   has_many :users_inclinations

   attr_accessible :description, :name, :low_label, :high_label
end

So you can pull the description (i.e. to build the rating form) from Inclinations and store the individual ratings with

an_inclination= Inclination.find_by_name('weather')
user.user_inclination.create(inclination: an_inclination, preference_score: the_users_score)