use`nec`;

 SET SQL_SAFE_UPDATES=0;

 ALTER TABLE `usr_user_info` CHANGE COLUMN `registerTime` `registerTime` BIGINT(20) NOT NULL COMMENT '注册时间' ,

 ALTER TABLE `usr_user_info` CHANGE COLUMN `lastLoginTime` `lastLoginTime` BIGINT(20) NULL DEFAULT NULL COMMENT '最后登录时间' ;

 UPDATE `usr_user_info` SET  `lastLoginTime` = unix_timestamp(`lastLoginTime`);

 UPDATE `usr_user_info` SET  `registerTime` = unix_timestamp(`registerTime`);

 --

 -- table alter for usr_user_info

 --

 /*增加字段*/

 use `nec`;

 ALTER TABLE `usr_user_info` ADD COLUMN tempRegisterTime BIGINT(20) NULL ;

 ALTER TABLE `usr_user_info`  ADD COLUMN tempLastLoginTime BIGINT(20) NULL ;

 /*进行时间转化，并复制列*/

 UPDATE  usr_user_info SET tempRegisterTime=unix_timestamp(registerTime);

 UPDATE  usr_user_info SET tempLastLoginTime=unix_timestamp(lastLoginTime);

 /*删除原有字段*/

 ALTER TABLE usr_user_info

     DROP registerTime,DROP lastLoginTime;

 /*更新临时字段名称*/

 ALTER TABLE usr_user_info CHANGE tempRegisterTime registerTime BIGINT(20) NOT NULL  COMMENT '注册时间';

 ALTER TABLE usr_user_info CHANGE tempLastLoginTime lastLoginTime BIGINT(20)  COMMENT '最近登录时间';