20130320032255_create_organizations.rb

class CreateOrganizations < ActiveRecord::Migration
  def change
    create_table :organizations do |t|
      t.string :name
      t.boolean :has_octocats

      t.timestamps
    end
  end
end

20130320032306_create_teams.rb

class CreateTeams < ActiveRecord::Migration
  def change
    create_table :teams do |t|
      t.string :name
      t.references :organization

      t.timestamps
    end
  end
end

organization.rb

class Organization < ActiveRecord::Base
  has_many :teams

  attr_accessible :name, :has_octocats

  scope :has_octocats_scope, lambda { where(:has_octocats => true) }

  def self.has_octocats_class_method
    where(:has_octocats => true)
  end
end

team.rb

class Team < ActiveRecord::Base
  belongs_to :organization
  attr_accessible :name

  def self.using_octocats_scope
    where(:organization_id => Organization.has_octocats_scope.select(:id))
  end

  def self.using_octocats_class_method
    where(:organization_id => Organization.has_octocats_class_method.select(:id))
  end
end