Question

I’m quite new to RoR. Sorry if I’m using wrong terminology or the answer is obvious.

Initially I had one model for users as follows,

class User
  include Mongoid::Document

  devise :database_authenticatable,
         :registerable,
         :recoverable,
         :rememberable,
         :trackable,
         :validatable,
         :token_authenticatable,
         :omniauthable

  has_many :foos
  field :name, :type => String
  # Some other company fields
  ....
end

class Foo
  include Mongoid::Document

  belongs_to :user
  ...
end

This initial User model used to represent a company.

Then I decided to add another model which will have a different role from the initial User model, so I started using polymorphic associations and moved the necessary fields from User to Company model. I also added a Manager model which is not directly related to Company. I basically use User model for devise.

class User
  include Mongoid::Document

  devise :database_authenticatable,
         :registerable,
         :recoverable,
         :rememberable,
         :trackable,
         :validatable,
         :token_authenticatable,
         :omniauthable

  belongs_to :rolable, :polymorphic => true
end

class Company
  include Mongoid::Document

  has_one :user, :as => :rolable

  has_many :foos
  field :name, :type => String
  # Some other company fields
  ....
end

class Manager
  include Mongoid::Document

  has_one :user, :as => rolable
end

class Foo
  include Mongoid::Document

  belongs_to :company
  ...
end

Everything seems to work fine so far for the new user registrations. However, there is the old database I have to convert. What confuses me is essentially the has_many association that I had before. I already implemented migration (using this gem, https://github.com/adacosta/mongoid_rails_migrations) to move the fields from User model to Company model, but again I couldn’t figure out how to deal with the associations.

Answer 1

You are not required to run your migration if you don’t need to transfer the information from your old database to your new one.

MongoDB can have some useless keys on document, there are no problems. The only problem you can have is to have extra octet saved on your database.