Retrieving non-AR columns with an AR query

region.rb

class Region < ActiveRecord::Base

  acts_as_nested_set :left_column => 'left', :right_column => 'right'

  attr_accessible :parent_id, :postcode, :name, :region_type
  attr_accessor :area                                       

  def self.suburb_search(terms, options={})                         
    options = {
      :limit => 20
    }.merge(options)
    
    self.select('regions.id, regions.name, regions.postcode, a.name AS "area"')    
        .where(:region_type => 'suburb')                                           
        .where(['regions.name LIKE ?', "#{terms}%"])                               
        .joins('LEFT OUTER JOIN regions a ON a.id = regions.parent_id')            
        .limit(options[:limit])
  end
end