表结构如下:CREATE TABLE `instance` (
`id` int(11) unsigned NOT NULL AUTO_INCREMENT,
`timestamp` int(10) unsigned DEFAULT NULL,
`cpu` decimal(8,3) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB;我每一分钟会往里面插入数据insert into `instance`(`id`,`timestamp`,`cpu`) values (1,1362455223,'1.200')
insert into `instance`(`id`,`timestamp`,`cpu`) values (2,1362455283,'0.410')如此下去现在我想得到 每5分钟或者每半个小时的平均值,怎么做求方法
`id` int(11) unsigned NOT NULL AUTO_INCREMENT,
`timestamp` int(10) unsigned DEFAULT NULL,
`cpu` decimal(8,3) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB;我每一分钟会往里面插入数据insert into `instance`(`id`,`timestamp`,`cpu`) values (1,1362455223,'1.200')
insert into `instance`(`id`,`timestamp`,`cpu`) values (2,1362455283,'0.410')如此下去现在我想得到 每5分钟或者每半个小时的平均值,怎么做求方法
from `instance`
group by `timestamp`-`timestamp`% (5*60)
这个SQL语句是个什么意思看不太明白