查看数据库编码：
root@localhost Wed Dec 13 11:21:00 2017 11:21:00 [liufofu]> show create database liufofu;+----------+-----------------------------------------------------------------+| Database | Create Database |+----------+-----------------------------------------------------------------+| liufofu | CREATE DATABASE `liufofu` /*!40100 DEFAULT CHARACTER SET gbk */ |+----------+-----------------------------------------------------------------+1 row in set (0.00 sec)修改数据库字符集：root@localhost Wed Dec 13 11:21:07 2017 11:21:07 [liufofu]> alter database liufofu default character set utf8;Query OK, 1 row affected (0.02 sec)查看数据库编码：root@localhost Wed Dec 13 11:21:17 2017 11:21:17 [liufofu]> show create database liufofu;+----------+------------------------------------------------------------------+| Database | Create Database |+----------+------------------------------------------------------------------+| liufofu | CREATE DATABASE `liufofu` /*!40100 DEFAULT CHARACTER SET utf8 */ |+----------+------------------------------------------------------------------+1 row in set (0.00 sec)root@localhost Wed Dec 13 11:21:20 2017 11:21:20 [liufofu]> create table fofu(id int ,username varchar(30));
Query OK, 0 rows affected (0.14 sec)查看表编码：root@localhost Wed Dec 13 11:21:48 2017 11:21:48 [liufofu]> show create table fofu;+-------+----------------------------------------------------------------------------------------------------------------| Table | Create Table +-------+----------------------------------------------------------------------------------------------------------------| fofu | CREATE TABLE `fofu` ( `id` int(11) DEFAULT NULL, `username` varchar(30) DEFAULT NULL) ENGINE=InnoDB DEFAULT CHARSET=utf8 |+-------+----------------------------------------------------------------------------------------------------------------1 row in set (0.00 sec)只是修改表的默认字符集：root@localhost Wed Dec 13 11:21:54 2017 11:21:54 [liufofu]> alter table fofu default character set gbk;Query OK, 0 rows affected (0.05 sec)Records: 0 Duplicates: 0 Warnings: 0查看表编码：root@localhost Wed Dec 13 11:22:15 2017 11:22:15 [liufofu]> show create table fofu;+-------+----------------------------------------------------------------------------------------------------------------| Table | Create Table +-------+----------------------------------------------------------------------------------------------------------------| fofu | CREATE TABLE `fofu` ( `id` int(11) DEFAULT NULL, `username` varchar(30) CHARACTER SET utf8 DEFAULT NULL) ENGINE=InnoDB DEFAULT CHARSET=gbk |+-------+----------------------------------------------------------------------------------------------------------------1 row in set (0.00 sec)把表默认的字符集和所有字符列（CHAR,VARCHAR,TEXT）改为新的字符集：root@localhost Wed Dec 13 11:22:18 2017 11:22:18 [liufofu]> alter table fofu convert to character set gbk; Query OK, 0 rows affected (0.30 sec)Records: 0 Duplicates: 0 Warnings: 0查看表编码：root@localhost Wed Dec 13 11:22:46 2017 11:22:46 [liufofu]> show create table fofu;+-------+----------------------------------------------------------------------------------------------------------------| Table | Create Table +-------+----------------------------------------------------------------------------------------------------------------| fofu | CREATE TABLE `fofu` ( `id` int(11) DEFAULT NULL,`username` varchar(30) DEFAULT NULL) ENGINE=InnoDB DEFAULT CHARSET=gbk |+-------+----------------------------------------------------------------------------------------------------------------1 row in set (0.00 sec)查看字段编码：root@localhost Wed Dec 13 11:22:49 2017 11:22:49 [liufofu]> show full columns from fofu; +----------+-------------+----------------+------+-----+---------+-------+---------------------------------+---------+| Field | Type | Collation | Null | Key | Default | Extra | Privileges | Comment |+----------+-------------+----------------+------+-----+---------+-------+---------------------------------+---------+| id | int(11) | NULL | YES | | NULL | | select,insert,update,references | || username | varchar(30) | gbk_chinese_ci | YES | | NULL | | select,insert,update,references | |+----------+-------------+----------------+------+-----+---------+-------+---------------------------------+---------+2 rows in set (0.00 sec)修改字段的字符集：root@localhost Wed Dec 13 11:23:10 2017 11:23:10 [liufofu]> alter table fofu change username username varchar(30) character set utf8;Query OK, 0 rows affected (0.35 sec)Records: 0 Duplicates: 0 Warnings: 0查看字段编码：root@localhost Wed Dec 13 11:24:01 2017 11:24:01 [liufofu]> show full columns from fofu; +----------+-------------+-----------------+------+-----+---------+-------+---------------------------------+---------+| Field | Type | Collation | Null | Key | Default | Extra | Privileges | Comment |+----------+-------------+-----------------+------+-----+---------+-------+---------------------------------+---------+| id | int(11) | NULL | YES | | NULL | | select,insert,update,references | || username | varchar(30) | utf8_general_ci | YES | | NULL | | select,insert,update,references | |+----------+-------------+-----------------+------+-----+---------+-------+---------------------------------+---------+2 rows in set (0.00 sec)