MySQL的经典用法(五)----触发器(转)

gaofeng0210

Sql代码
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`)
)
Sql代码
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;