attr_encrypted.rb

class AddColumnsForAttrEncrypted < ActiveRecord::Migration[5.2]
  def change
    tasks = {
      alipays:                 [:private_key],
      crawlers:                [:username, :password],
      delivery_platforms:      [:key, :secret, :brand_key, :sid],
      meituans:                [:api_key],
      wechat_service_accounts: [:wechat_pay_api_key, :wechat_pay_certificate]
    }

    tasks.each_pair do |table_name, columns|
      klass = table_name.to_s.classify.constantize

      columns.each do |column|
        column_type = klass.type_for_attribute(:"encrypted_#{column}").type

        add_column table_name, column, column_type
      end
    end

    reversible do |direction|
      direction.up do
        tasks.each_pair do |table_name, columns|
          klass = table_name.to_s.classify.constantize

          columns.each do |column|

            klass.all.each do |record|
              begin
                value = record.send(column)
                record.update_column(column, value)
              rescue => ex
                logger.error { ex.inspect }
              end
            end
          end
        end
      end
    end
  end
end