rails many to many self join

by

I’d use something like

class Person < ActiveRecord::Base
   has_many :friendships, :foreign_key => "person_id", 
      :class_name => "Friendship"

   has_many :friends, :through => :friendships
end

class Friendship < ActiveRecord::Base
   belongs_to :person, :foreign_key => "person_id", :class_name => "Person"
   belongs_to :friend, :foreign_key => "friend_id", :class_name => "Person"  
end

And the tables would be like

people: id; name; whatever-you-need    
friendships: id; person_id; friend_id

More Related Contents:

  1. Explain like I'm LITERALLY five…what does it mean to "format" a string? [closed]
  2. How to change default timezone for Active Record in Rails?
  3. Why can you not have a foreign key in a polymorphic association?
  4. Passing parameters in rails redirect_to
  5. Rails 4 Authenticity Token
  6. Rails 5: ActiveRecord OR query
  7. How can I download a file from a URL and save it in Rails?
  8. Ruby on Rails. How do I use the Active Record .build method in a :belongs to relationship?
  9. rake db:schema:load vs. migrations
  10. Change from SQLite to PostgreSQL in a fresh Rails project
  11. instance variable vs. symbol in ruby on rails (form_for)
  12. Set start date and expiration date for Rails cookies
  13. Getting the warning “Insecure world writable dir /home/chance ” in PATH, mode 040777 for rails and gem
  14. find vs find_by vs where
  15. rails built in datetime validation
  16. What is the best way to seed a database in Rails?
  17. Cannot add a NOT NULL column with default value NULL in Sqlite3
  18. Bulk Insert records into Active Record table
  19. Rails: Multi-submit buttons in one Form
  20. How does load differ from require in Ruby?
  21. What to use instead of `render :text` (and `render nothing: true`) in rails 5.1 and later?
  22. Rails 4.0 Strong Parameters nested attributes with a key that points to a hash
  23. Rails dot instead of slash in URL
  24. Request origin not allowed: http://localhost:3001 when using Rails5 and ActionCable
  25. How can I remove a default gem? ! want to uninstall a gem 1.7.7 version of json
  26. Upgrading from Rails 2.3.8 to 4.0
  27. rails 3 + devise: how to modify the mailer method for confirmation emails to add user’s second email address
  28. jQuery post to Rails
  29. RubyInstaller 2.2.1 and Rails – Rake cannot load Nokogiri
  30. Rails Object Relationships and JSON Rendering

Leave a Comment