SSL setup: https://vimeo.com/209534466

rails g migration CreateJoinTableGameInvitesInvitees game_invites invitees

• Models linked together must be in alphabetical order when naming the migration file
• the columns can be given any names as long as they are correctly associated in the model file:

has_and_belongs_to_many :invitees, class_name: 'User', foreign_key: 'invitee_id', #the associated column and the alien model
                        join_table: 'game_invites_invitees', #name of the join table
                        association_foreign_key: 'game_invite_id' #the name of the domestic model in the join table

Original article

Supposing we are using Postgre as a database, it only takes the following steps to use UUIDs as database IDs instead of incremental ones:

1. Generate a migration: rails g migration EnablePgcryptoExtension
2. Modify the migration file to this:

class EnablePgcryptoExtension < ActiveRecord::Migration[5.1]
  def change
    enable_extension 'pgcrypto'
  end
end

3. Tell ActiveRecord that the new generator for IDs should be UUIDs:

#config/application.rb 
config.generators do |g|
  g.orm :active_record, primary_key_type: :uuid
end