Rails: db tables and related models

Hi Osgaldor!

This in not convoluted at all, and in fact this is what makes Rails (and Ruby) so fun to use! Your logic is absolutely correct. There are a couple of ways to go about this, but I personally like to use the has_many through method. I will demonstrate below.

So, given we are setup like you have described above (if I'm following correctly!)

class Inbox < ActiveRecord::Base

  belongs_to :user
  has_many :messages

end

class Message < ActiveRecord::Base

  belongs_to :inbox

end

Now setting up the User model so it can get a list of all messages is as simple as this

class User < ActiveRecord::Base

  has_many :inboxes
  has_many :messages, through: :inbox

end

Essentially what ActiveRecord is going to give us is ALL the messages no matter how many inboxes a user has. You can define more methods on your user model to customize the results. For example, given there is an inbox with a name attribute of 'Spam' and I wanted to call a method on a user instance to get a list of all the spam mail, I would write it like this:

class User < ActiveRecord::Base

  has_many :inboxes
  has_many :messages, through: :inbox

  def spam
    messages.where('inboxes.name = ?', 'Spam')
  end

end

Now if I find a user I can get a list of their spam

class InboxesController < ApplicationController

  def spam
    @user = User.find(params[:user_id])
    @spam_mail = @user.spam
  end

end

I hope this helps!