mysql数据库CURRENT_TIMESTAMP时间戳

登录mysql，在test数据库中新建 一个表，shijian字段是timestamp 类型，默认是CURRENT_TIMESTAMP ，只要增加更新shijian字段会变为当前时间： Create Table CREATE TABLE `chengshi` (  `id` int(11) NOT NULL AUTO_INCREMENT,  `shengfen` varchar(10) DEFAULT NULL,  `chengshi` varchar(10) DEFAULT NULL,  `shijian` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,  PRIMARY KEY (`id`)) ENGINE=InnoDB AUTO_INCREMENT=10 DEFAULT CHARSET=utf8

在表中增加一些数据：insert into `chengshi` (`id`, `shengfen`, `chengshi`, `shijian`) values('1','河南','安阳','2019-03-05 10:14:27');insert into `chengshi` (`id`, `shengfen`, `chengshi`, `shijian`) values('2','河南','郑州','2019-03-05 10:14:27');insert into `chengshi` (`id`, `shengfen`, `chengshi`, `shijian`) values('3','河南','洛阳','2019-03-05 10:14:27');insert into `chengshi` (`id`, `shengfen`, `chengshi`, `shijian`) values('4','河南','漯河','2019-03-05 10:14:27');insert into `chengshi` (`id`, `shengfen`, `chengshi`, `shijian`) values('5','河南','新乡','2019-03-05 10:14:27');insert into `chengshi` (`id`, `shengfen`, `chengshi`, `shijian`) values('6','河南','濮阳','2019-03-05 10:14:27');insert into `chengshi` (`id`, `shengfen`, `chengshi`, `shijian`) values('7','河南','焦作','2019-03-05 10:14:27');insert into `chengshi` (`id`, `shengfen`, `chengshi`, `shijian`) values('8','河南','鹤壁','2019-03-05 10:14:27');insert into `chengshi` (`id`, `shengfen`, `chengshi`, `shijian`) values('9','河南','开封','2019-03-05 10:14:27');

时间戳基本的用法，它表示当前时间：SELECT CURRENT_TIMESTAMP,NOW();

在表中增加一个数据，看shijian字段为登记时间，INSERT INTO chengshi(shengfen,chengshi)VALUES('河南','信阳');

查询表中所有数据：SELECT * FROM chengshi;shijian字段变成录入时间。

查询表中所有数据：SELECT * FROM chengshi;shijian字段变成更新时间。