Dump Rails 2.3 Ruby 1.8 ActiveRecord Objects to CSV

dump_old_rails.rb

require 'csv'

class ActiveRecord::Base
  class << self
    def dump_all
      descendants.each(&:to_csv)
      nil
    end

    def to_csv(filename=csv_export_filename)
      CSV.generate(filename) do |csv|
        csv << column_names
        with_exclusive_scope do
          find_in_batches do |objs|
            objs.each do |obj|
              csv << column_names.map { |attr| obj.send(attr) }
            end
          end
        end
      end
    end

    def csv_export_filename
      "#{class_name.underscore}-#{Date.current.to_s}.csv"
    end

    def descendants
      ObjectSpace.each_object(Class).select { |klass| klass < self }
    end
  end
end

ActiveRecord::Base.dump_all