class ReadingsGoPolymorphic < ActiveRecord::Migration
  def self.up
    rename_column(:readings, :support_material_id, :readable_id)
    add_column(:readings, :readable_type, :string)
  end

  def self.down
    rename_column(:readings, :readable_id, :support_material_id)
    remove_column(:readings, :readable_type)
  end
end
