# File lib/active_record/base.rb, line 953
      def update_counters(id, counters)
        updates = counters.inject([]) { |list, (counter_name, increment)|
          sign = increment < 0 ? "-" : "+"
          list << "#{connection.quote_column_name(counter_name)} = COALESCE(#{connection.quote_column_name(counter_name)}, 0) #{sign} #{increment.abs}"
        }.join(", ")

        if id.is_a?(Array)
          ids_list = id.map {|i| quote_value(i)}.join(', ')
          condition = "IN  (#{ids_list})"
        else
          condition = "= #{quote_value(id)}"
        end

        update_all(updates, "#{connection.quote_column_name(primary_key)} #{condition}")
      end