MQTT

INSERT INTO `topics` (`site`, `node`, `topic`) VALUES
(1, 1, 's1/n1/noise/decibels'),
(1, 2, 's1/n2/noise/decibels'),
(1, 3, 's1/n3/noise/decibels');

CREATE TABLE `sensors` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `num` int(11) NOT NULL,
  `sensor` double,
  `tstamp` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;