ActiveRecord, Arel and Oj

ar_arel_oj.rb

require 'activerecord'
require 'oj'
require 'json'

# Some ActiveRecord inherited class
class SomeARClass < ActiveRecord::Base
  # Find a record from the database as hash without AR object initialization
  def self.lightning id
    # Connection = Database Adapter = Mysql2Adapter
    connection.select(where(:id => id).to_sql).each do |attrs|
      attrs.each do |attr|
        attrs[attr] = type_cast_attribute(attr, attrs)
      end
    end[0]
  end
end

json = Oj.dump SomeArClass.lightning(1), :mode => :compat
JSON.parse json