migration.rb

class ConvertLoginInstructionFromHtmlToMarkdownInBrands < ActiveRecord::Migration
  def self.up
    Brand.find_each do |brand|
      brand.login_instruction = ReverseMarkdown.parse(brand.login_instruction)
      brand.save
    end
  end

  def self.down
    renderer = Redcarpet::Render::HTML.new(:filter_html => true)
    markdown = Redcarpet::Markdown.new(renderer)

    Brand.find_each do |brand|
      brand.login_instruction = markdown.render(brand.login_instruction)
      brand.save
    end
  end
end