MySQL中UPDATE语句使用的实例教程

DROP TABLE IF EXISTS t_test;
CREATE TABLE t_test (
 bs bigint(20) NOT NULL auto_increment,
 username varchar(20) NOT NULL,
 password varchar(20) default NULL,
 remark varchar(200) default NULL,
 PRIMARY KEY (bs)
) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=gbk;
 
 
INSERT INTO t_test VALUES (1,'lavasoft','123456',NULL);
INSERT INTO t_test VALUES (2,'hello',NULL,NULL);
INSERT INTO t_test VALUES (3,'haha',zz,tt);

update t_test t 
  set t.password = '***' 
 where t.bs = 2;

update t_test t 
  set t.password = '*', t.remark = '*' 
 where t.bs = 1;

update t_test t 
  set t.password = null, t.remark = null 
 where t.bs = 3;

UPDATE table_anem SET column_name1 = value1, column_name2 = value2,  WHERE ;

UPDATE users SET age = 24 WHERE id = 123;

UPDATE users SET age = 24, name = 'Mike' WHERE id = 123;

update ONE，TWO 
set ONE.AGE=TWO.AGE 
where ONE.ID=TWO.ID AND ONE.AGE != TWO.AGE 

CREATE TABLE `tmp_open_ip` (
 `email` varchar(60) NOT NULL DEFAULT '',
 `address` varchar(50) NOT NULL DEFAULT '',
 `ip` int(10) unsigned NOT NULL DEFAULT '0',
 KEY `email` (`email`),
 KEY `ip` (`ip`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8

CREATE TABLE `ip` (
`s` int(10) unsigned NOT NULL DEFAULT '0' COMMENT '开始ip',
`e` int(10) unsigned NOT NULL DEFAULT '0' COMMENT '结束ip',
`a` varchar(50) NOT NULL DEFAULT '',
KEY `s` (`s`),
KEY `e` (`e`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8

UPDATE tmp_open_ip AS u 
INNER JOIN ip 
ON u.ip BETWEEN ip.s AND ip.e 
SET u.address = ip.a

CREATE TABLE `tmp_open_address` (
`email` varchar(60) NOT NULL DEFAULT '',
`address` varchar(50) NOT NULL DEFAULT '',
`ip` int(10) unsigned NOT NULL DEFAULT '0'
) ENGINE=MyISAM DEFAULT CHARSET=utf8

insert into tmp_open_address (email,address,ip)
select l.email,ip.a,l.ip
 from tmp_open_log as l inner join ip on l.ip between ip.s and ip.e ;
/* Affected rows: 2,543,124 Found rows: 0 Warnings: 0 Duration for 3 queries: 16.922 sec. */

SELECT * FROM `tmp_open_ip` where address!=''