Active Record 序列化

# File activerecord/lib/active_record/serialization.rb, line 13
def serializable_hash(options = nil)
  if self.class._has_attribute?(self.class.inheritance_column)
    options = options ? options.dup : {}

    options[:except] = Array(options[:except]).map(&:to_s)
    options[:except] |= Array(self.class.inheritance_column)
  end

  super(options)
end