mysql修改数据库编码字段编码

//创建数据库并指定编码

create database `test` default character set utf8mb4 collate utf8mb4_unicode_ci

//浏览器打印出unicode编码字符

varff=‘\u660e\u5929\uff0c\u4f60\u597d \ue115‘

//修改表的字段

alter table `tablename` change `dd` `dd` varchar(45) character set utf8 collate utf8_bin NOT NULL

alter table `hd_wall` modify column `content` varchar(150) character set utf8mb4 collate utf8mb4_unicode_ci NOT NULL DEFAULT ‘‘ COMMENT ‘消息内容‘,

alter table `hd_sign` modify column `nickname` varchar(50) character set utf8mb4 collate utf8mb4_unicode_ci NULL COMMENT ‘昵称‘;

//显示当前数据库编码

show VARIABLES where Variable_name LIKE ‘character\_set\_%‘ OR Variable_name LIKE ‘collation%‘;

//linux重启mysql

1、 使用 service 启动：service mysqld restart

2、使用 mysqld 脚本启动：/etc/init.d/mysqld restart

sql时间格式化

select unix_timestamp("2015-09-08");

select from_unixtime(sign_time,‘%Y-%m-%d %H:%i‘) from hd_sign;