def ignore_columns(*columns)
      self.ignored_columns ||= []
      self.ignored_columns += columns.map(&:to_s)
      reset_column_information
      descendants.each(&:reset_column_information)
      self.ignored_columns.tap(&:uniq!)
    end
def ignore_columns(*columns)
      self.ignored_columns ||= []
      self.ignored_columns += columns.map(&:to_s)
      reset_column_information
      descendants.each(&:reset_column_information)
      self.ignored_columns.tap(&:uniq!)
    end
Prevent Rails from loading a table column.
 Useful for legacy database schemas with problematic column names,
 like 'class' or 'attributes'.

   class Topic < ActiveRecord::Base
     ignore_columns :attributes, :class
   end

   Topic.new.respond_to?(:attributes) => false