instance method handle_warnings

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 753
        def handle_warnings(sql)
          return if ActiveRecord.db_warnings_action.nil? || @raw_connection.warning_count == 0

          @affected_rows_before_warnings = @raw_connection.affected_rows
          result = @raw_connection.query("SHOW WARNINGS")
          result.each do |level, code, message|
            warning = SQLWarning.new(message, code, level, sql, @pool)
            next if warning_ignored?(warning)

            ActiveRecord.db_warnings_action.call(warning)
          end
        end