class ChangeAttachmentTime < ActiveRecord::Migration
  def up
    Attachment.where("container_type = 'Course'").each do |attachment|
      if attachment.container && attachment.container.created_at.to_i > attachment.created_on.to_i
        attachment.created_on = attachment.container.created_at + 3600 * 24
        attachment.save
      end
    end
  end

  def down
  end
end