update_counter_in_database

# File activerecord/lib/active_record/associations/has_many_association.rb, line 107
        def update_counter_in_database(difference, reflection = reflection())
          if has_cached_counter?(reflection)
            counter = cached_counter_attribute_name(reflection)
            owner.class.update_counters(owner.id, counter => difference)
          end
        end