class AddTargetFieldsToGalleryPicture < ActiveRecord::Migration
  def self.up
    add_column :gallery_pictures, :target_id,  :integer
    add_column :gallery_pictures, :target_type,  :string
    GalleryPicture.where("gallery_id is not null").each do |picture|
      picture.target_type = "Gallery"
      picture.target_id = picture.gallery_id
      picture.save
    end
    remove_column :gallery_pictures, :gallery_id
  end

  def self.down
    add_column :gallery_pictures, :gallery_id, :integer
    GalleryPicture.where(:target_type => "Gallery").each do |picture|
      picture.gallery_id = picture.target_id
      picture.save
    end
    add_column :gallery_pictures, :gallery_id, :integer
    remove_column :gallery_pictures, :target_id
    remove_column :gallery_pictures, :target_type
  end
end