MySQL的經典用法(五)----觸發器

MySQL的經典用法(五)----觸發器

CREATE TABLE `vardata` (
  `Id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(255) DEFAULT NULL,
  `time` datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
  `data` double(15,5) DEFAULT '-601.00000',
  PRIMARY KEY (`Id`,`time`),
  UNIQUE KEY `unique` (`name`,`time`)
)

CREATE TABLE `vardata_compute` (
  `Id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(255) DEFAULT NULL,
  `time` datetime DEFAULT NULL,
  `data` double(15,5) DEFAULT NULL,
  PRIMARY KEY (`Id`)
)

CREATE TABLE `vardata` (
  `Id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(255) DEFAULT NULL,
  `time` datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
  `data` double(15,5) DEFAULT '-601.00000',
  PRIMARY KEY (`Id`,`time`),
  UNIQUE KEY `unique` (`name`,`time`)
)

CREATE TABLE `vardata_compute` (
  `Id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(255) DEFAULT NULL,
  `time` datetime DEFAULT NULL,
  `data` double(15,5) DEFAULT NULL,
  PRIMARY KEY (`Id`)
) 

DROP TRIGGER IF EXISTS trigger_insert_59data;
CREATE TRIGGER trigger_insert_59data
AFTER INSERT
ON vardata
FOR EACH ROW
BEGIN
     DECLARE time_59 DateTime;
     SET time_59 = NEW.time-INTERVAL 1 SECOND;
     IF MINUTE(NEW.time)=0 AND SECOND(NEW.time)=0 THEN
        INSERT INTO vardata_compute SET name=NEW.name,time=time_59,data=NEW.data;
     END IF;
END;

DROP TRIGGER IF EXISTS trigger_delete_59data;
CREATE TRIGGER trigger_delete_59data
AFTER DELETE
ON vardata
FOR EACH ROW
BEGIN
     DECLARE time_59 DateTime;
     SET time_59 = OLD.time-INTERVAL 1 SECOND;
     IF MINUTE(OLD.time)=0 AND SECOND(OLD.time)=0 THEN
        DELETE FROM vardata_compute WHERE time=time_59 AND name=old.name;
     END IF;
END;

DROP TRIGGER IF EXISTS trigger_update_59data;
CREATE TRIGGER trigger_update_59data
AFTER UPDATE
ON vardata
FOR EACH ROW
BEGIN
     DECLARE time_59 DateTime;
     SET time_59 = NEW.time-INTERVAL 1 SECOND;
     IF MINUTE(NEW.time)=0 AND SECOND(NEW.time)=0 THEN
        UPDATE vardata_compute SET data=NEW.data WHERE time=time_59 AND name=NEW.name;
     END IF;
END;