arel_alias_attribute.rb

module Arel::AliasAttribute
  def alias_attribute(new_name, old_name)
    attribute_aliases.update(new_name.to_s => old_name.to_s)
  end

  def [](name)
    super attribute_aliases[name.to_s] || name
  end

  def attribute_aliases
    @attribute_aliases ||= {}
  end
end

Arel::Table.__send__(:prepend, Arel::AliasAttribute)