CODEWITHSUNDEEP
ruby-on-railsruby-on-rails-3.1
rmagnum2002
rmagnum2002

Reputation: 11421

rails 3.1 relations between records from the same model

I have a model called massmedia and this model belongs to company.

We have companies: PRIME, JURNAL, ASMEDIA, MEDIA GROUP

and massmedia: PRIME TV, JURNAL TV, JURNAL FM, PUBLIKA TV

and the relation:

 Company                        TV Channel                    Company

1. **PRIME**        owner of   **PRIME TV**

2. **JURNAL**       owner of   **JURNAL TV**

3. **ASMEDIA**      owner of   **PUBLIKA TV**    owner of     **PRIME**

4. **MEDIA GROUP**                               owner of     **PRIME**

Now I got into problem where company PRIME is owned by ASMEDIA and MEDIA GROUP and that means I have to relate company to company and I am not sure if this can be done, even creating a new table for relation between 2 companies it's not good as I would need a table with 2 columns company_id of owned company and company_id of the one hwo owns it.

Any ideas how can I solve this? Thank you.

EDIT

I tried to create a scheme of what I tried to accomplish:

MediaGrup is the owner of the company Prime and companies shareholder 1 and 2 are the owners of MediaGrup

so all of them: MediaGrup, Shareholder1 and 2 are in company model.

enter image description here

Upvotes: 0

Views: 61

Answers (1)

Baldrick
Baldrick

Reputation: 24340

You can have relations between instances of the same classe. For example with has_one and belongs_to (it possible also with has_many, but your example shows no 0..n association) :

class MassMedia< ActiveRecord::Base   # the table "mass_medias" must have a column 'owner_id'
  belongs_to :owner, :class_name => 'Company', :foreign_key => 'owner_id', :inverse_of => :mass_media
end

class Company < ActiveRecord::Base   # the table "companies" must have a column 'owner_id'
  has_one :mass_media, :inverse_of => :owner

  has_one :company, :inverse_of => :owner      
  belongs_to :owner, :class_name => 'Company', :foreign_key => 'owner_id', :inverse_of => :company
end

Upvotes: 1

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