view db/migrate/20090406161854_add_parent_id_to_enumerations.rb @ 1549:28cde511f312 feature_1136

Force flag is needed here

class AddParentIdToEnumerations < ActiveRecord::Migration
  def self.up
    add_column :enumerations, :parent_id, :integer, :null => true, :default => nil
  end

  def self.down
    remove_column :enumerations, :parent_id
  end
end