hstore_translate existing data migration

I've added hstore_translate to a Rails4 project with existing data.

class Product < ActiveRecord::Base
  translates :subtitle, :description
end

config.i18n.fallbacks = true

class AddTranslationColumnsToProducts < ActiveRecord::Migration
  def change
    add_column :products, :subtitle_translations, :hstore
    add_column :products, :description_translations,  :hstore
  end
end

How can I access my old subtitle and description fields? Because now Post.subtitle and Post.description always nil. Fallback doesn't work or I need migrate data first?

upd:

This migration solves problem.

class MigrateExistingDataToTranslations < ActiveRecord::Migration
  def change
    execute "UPDATE products p SET subtitle_translations=hstore('en',(select subtitle from products where id = p.id));"
    execute "UPDATE products p SET description_translations=hstore('en', (select description from products where id = p.id));"
  end
end

hstore_translate defines methods to read the various translations.

When defining translates :subtitle, :description, the methods subtitle & description are created, which gets the fitting translation. So when calling Product.subtitle, instead of getting the column and its data it is calling the method.

To access the data temporarily you should comment out the hstore_translate setup

class Product < ActiveRecord::Base
  # translates :subtitle, :description
end

Then merge your data to the new columns before uncommenting again.