# File lib/active_record/base.rb, line 832 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(", ") update_all(updates, "#{connection.quote_column_name(primary_key)} = #{quote_value(id)}") end