<%# migration for ActiveRecord 3.0 -%>
class <%= migration_classname %> < ActiveRecord::Migration
  def self.up
    add_column :<%= table_name %>, :<%= sign_attribute.underscore %>, :integer
    add_index  :<%= table_name %>, :<%= sign_attribute.underscore %>
    
    <%= model_classname %>.all.each do |<%= model_name.underscore.singularize %>|
      <%= model_name.underscore.singularize %>.send(:update_sign_id)
      <%= model_name.underscore.singularize %>.save
    end
  end
  
  def self.down
    remove_index  :<%= table_name %>, :<%= sign_attribute.underscore %>
    remove_column :<%= table_name %>, :<%= sign_attribute.underscore %>
  end
end