查看修改MySQL字符集

http://blog.sina.com.cn/s/blog_70ac6bec01016fts.html

查看修改MySQL字符集

(2012-08-22 09:53:21)

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字符集

mysql数据库

mysql字符集查看

mysql启动命令

修改mysql字符集

分类：网站开发

MySQL字符集多种多样，下面为列举了其中三种最常见的字符集查看方法，该方法供您参考，希望对学习MySQL数据库能有所启迪。

一、查看MySQL数据库服务器和数据库MySQL字符集。

mysql> show variables like '%char%';
+--------------------------+-------------------------------------+------
| Variable_name | Value |......
+--------------------------+-------------------------------------+------
| character_set_client | utf8 |...... -- 客户端字符集
| character_set_connection | utf8 |......
| character_set_database | utf8 |...... -- 数据库字符集
| character_set_filesystem | binary |......
| character_set_results | utf8 |......
| character_set_server | utf8 |...... -- 服务器字符集
| character_set_system | utf8 |......
| character_sets_dir | D:\MySQL Server 5.0\share\charsets\ |......
+--------------------------+-------------------------------------+------

mysql的字符集分为几类 A.客户端字符集：通过系统变量”character_set_client“表示，通知server端，客户端提交的sql语句编码格式 B.连接字符集：通过系统变量”character_set_connectiont“表示，server端翻译sql语句时，使用的编码格式 C.结果集字符集：通过系统变量”character_set_results“表示，server端返回结果集之前把结果集转换成的编码格式 D.存储字符集：通过系统变量”character_set_results“和“character_set_server”表示，是数据在存储引擎里编码格式

为了不出现乱码，我们需要统一修改这些参数，比如我要把数据库的默认字符集改为utf8，如下所示

在[client]下添加如下参数 default-character-set=utf8

在[mysqld]下添加如下参数 default-character-set=utf8

然后重启mysql服务，再查看字符集（要重新登录客户端）

mysql>

mysql>

mysql的字符集分的比较细，可以采用默认值，也可以指定值

A.数据库字符集

使用默认字符集的库 mysql> create database db1; Query OK, 1 row affected (0.01 sec)

mysql> show create database db1; +----------+--------------------------------------------------------------+ | Database | Create Database | +----------+--------------------------------------------------------------+ | db1 | CREATE DATABASE `db1` | +----------+--------------------------------------------------------------+ 1 row in set (0.00 sec)

指定字符集的库 mysql> create database db2 default character set latin1; Query OK, 1 row affected (0.01 sec)

mysql> show create database db2; +----------+----------------------------------------------------------------+ | Database | Create Database | +----------+----------------------------------------------------------------+ | db2 | CREATE DATABASE `db2` | +----------+----------------------------------------------------------------+ 1 row in set (0.00 sec)

修改库的字符集 mysql> alter database db2 default character set utf8; Query OK, 1 row affected (0.00 sec)

mysql> show create database db2; +----------+--------------------------------------------------------------+ | Database | Create Database | +----------+--------------------------------------------------------------+ | db2 | CREATE DATABASE `db2` | +----------+--------------------------------------------------------------+ 1 row in set (0.00 sec)

B.表字符集

mysql> use db2; Database changed

使用默认库字符集的表 mysql> create table t1(a varchar(10)); Query OK, 0 rows affected (0.01 sec)

mysql> show create table t1; +-------+-----------------------------------------------------------------------------------------+ | Table | Create Table | +-------+-----------------------------------------------------------------------------------------+ | t1 | CREATE TABLE `t1` ( `a` varchar(10) default NULL ) ENGINE=InnoDB DEFAULT CHARSET=utf8 | +-------+-----------------------------------------------------------------------------------------+ 1 row in set (0.00 sec)

创建指定字符集的表 mysql> create table t2(a varchar(10)) default character set latin1;; Query OK, 0 rows affected (0.01 sec)

ERROR: No query specified

mysql> show create table t2; +-------+-------------------------------------------------------------------------------------------+ | Table | Create Table | +-------+-------------------------------------------------------------------------------------------+ | t2 | CREATE TABLE `t2` ( `a` varchar(10) default NULL ) ENGINE=InnoDB DEFAULT CHARSET=latin1 | +-------+-------------------------------------------------------------------------------------------+ 1 row in set (0.00 sec)

更改表的字符集 mysql> alter table t2 default character set utf8; Query OK, 0 rows affected (0.01 sec) Records: 0 Duplicates: 0 Warnings: 0

mysql> show create table t2; +-------+--------------------------------------------------------------------------------------------------------------+ | Table | Create Table | +-------+--------------------------------------------------------------------------------------------------------------+ | t2 | CREATE TABLE `t2` ( `a` varchar(10) character set latin1 default NULL ) ENGINE=InnoDB DEFAULT CHARSET=utf8 | +-------+--------------------------------------------------------------------------------------------------------------+ 1 row in set (0.00 sec)

mysql>

从上面可以看到，修改表的字符集时，不会影响已经存在列的字符集，但新增列将继承表的字符集，如下

mysql> alter table t2 add a2 varchar(10); Query OK, 0 rows affected (0.01 sec) Records: 0 Duplicates: 0 Warnings: 0

mysql> show create table t2; +-------+-----------------------------------------------------------------------------------------------------------------------------------------------+ | Table | Create Table | +-------+-----------------------------------------------------------------------------------------------------------------------------------------------+ | t2 | CREATE TABLE `t2` ( `a` varchar(10) character set latin1 default NULL, `a2` varchar(10) default NULL ) ENGINE=InnoDB DEFAULT CHARSET=utf8 | +-------+-----------------------------------------------------------------------------------------------------------------------------------------------+ 1 row in set (0.01 sec)

mysql>

如果想更改已经存在表和字符列的字符集，要用如下

mysql> alter table t2 convert to character set latin1; Query OK, 0 rows affected (0.01 sec) Records: 0 Duplicates: 0 Warnings: 0

mysql> show create table t2; +-------+----------------------------------------------------------------------------------------------------------------------------+ | Table | Create Table | +-------+----------------------------------------------------------------------------------------------------------------------------+ | t2 | CREATE TABLE `t2` ( `a` varchar(10) default NULL, `a2` varchar(10) default NULL ) ENGINE=InnoDB DEFAULT CHARSET=latin1 | +-------+----------------------------------------------------------------------------------------------------------------------------+ 1 row in set (0.01 sec)

C.字段字符集

使用默认和指定字符集创建的列 mysql> create table t3 (a1 varchar(10),a2 varchar(10) character set latin1); Query OK, 0 rows affected (0.04 sec)

mysql> show create table t3; +-------+------------------------------------------------------------------------------------------------------------------------------------------------+ | Table | Create Table | +-------+------------------------------------------------------------------------------------------------------------------------------------------------+ | t3 | CREATE TABLE `t3` ( `a1` varchar(10) default NULL, `a2` varchar(10) character set latin1 default NULL ) ENGINE=InnoDB DEFAULT CHARSET=utf8 | +-------+------------------------------------------------------------------------------------------------------------------------------------------------+ 1 row in set (0.00 sec)

mysql>

修改列的字符集 mysql> alter table t3 change a2 a2 varchar(10) character set utf8; Query OK, 0 rows affected (0.03 sec) Records: 0 Duplicates: 0 Warnings: 0

mysql>

结论：字符集从数据库、表、列的字符集是逐级继承的关系

查看字符集命令 mysql> show create table t4; //显示表字符集 mysql> show create database db2; //显示库字符集 mysql> show full columns from t4; //显示列字符集

alter database db2 default character set utf8; //更改库的字符集 alter table t2 convert to character set latin1;//更改表的现存列字符集 alter table t2 default character set utf8; //更能改表的默认字符集 alter table t3 change a2 a2 varchar(10) character set utf8; //更能改字段的字符集

2.修改mysql的默认存储引擎

mysql>

在[mysqld]下添加如下参数 default-storage-engine=innodb

重启mysql服务，查看

mysql>

创建默认字符集的表 mysql> create table t4 (a1 int); Query OK, 0 rows affected (0.01 sec)

mysql> show create table t4; +-------+--------------------------------------------------------------------------------------+ | Table | Create Table | +-------+--------------------------------------------------------------------------------------+ | t4 | CREATE TABLE `t4` ( `a1` int(11) default NULL ) ENGINE=InnoDB DEFAULT CHARSET=utf8 | +-------+--------------------------------------------------------------------------------------+ 1 row in set (0.00 sec)

更改表的默认字符集 mysql> alter table t4 engine myisam; Query OK, 0 rows affected (0.06 sec) Records: 0 Duplicates: 0 Warnings: 0

mysql> show create table t4; +-------+--------------------------------------------------------------------------------------+ | Table | Create Table | +-------+--------------------------------------------------------------------------------------+ | t4 | CREATE TABLE `t4` ( `a1` int(11) default NULL ) ENGINE=MyISAM DEFAULT CHARSET=utf8 | +-------+--------------------------------------------------------------------------------------+ 1 row in set (0.00 sec)

mysql>

二、查看MySQL数据表（table）的MySQL字符集。

mysql> show table status from sqlstudy_db like '%countries%';
+-----------+--------+---------+------------+------+-----------------+------
| Name | Engine | Version | Row_format | Rows | Collation |......
+-----------+--------+---------+------------+------+-----------------+------
| countries | InnoDB | 10 | Compact | 11 | utf8_general_ci |......
+-----------+--------+---------+------------+------+-----------------+------

三、查看MySQL数据列（column）的MySQL字符集。

mysql> show full columns from countries;
+----------------------+-------------+-----------------+--------
| Field | Type | Collation | .......
+----------------------+-------------+-----------------+--------
| countries_id | int(11) | NULL | .......
| countries_name | varchar(64) | utf8_general_ci | .......
| countries_iso_code_2 | char(2) | utf8_general_ci | .......
| countries_iso_code_3 | char(3) | utf8_general_ci | .......
| address_format_id | int(11) | NULL | .......
+----------------------+-------------+-----------------+--------

MySQL修改默认字符集

修改mysql的默认字符集是通过修改它的配置文件来实现的。一般分两种情况：

方法一:

Windows平台

windows下的mysql配置文件是my.ini

一般在C:\Program Files\MySQL\MySQL Server 5.0

default-character-set=gbk #或gb2312,big5,utf8 然后重新启动mysql:运行->services.msc->停止MySql->启动 OK

或 /etc/init.d/mysql restart 或用其他方法重新启动，就生效了。

Unix平台 linux下的mysql配置文件是my.cnf

一般是/etc/my.cnf，如果找不到可以用find命令找一下： find / -iname my.cnf 在这个文件里面加上 default-character-set=gbk #或gb2312,big5,utf8 然后重新启动mysql net stop mysql net start mysql

方法二:

通过MySQL命令行修改:
mysql> set character_set_client=utf8;
Query OK, 0 rows affected (0.00 sec)
mysql> set character_set_connection=utf8;
Query OK, 0 rows affected (0.00 sec)
mysql> set character_set_database=utf8;
Query OK, 0 rows affected (0.00 sec)
mysql> set character_set_results=utf8;
Query OK, 0 rows affected (0.00 sec)
mysql> set character_set_server=utf8;
Query OK, 0 rows affected (0.00 sec)
mysql> set character_set_system=utf8;
Query OK, 0 rows affected (0.01 sec)
mysql> set collation_connection=utf8;
Query OK, 0 rows affected (0.01 sec)
mysql> set collation_database=utf8;
Query OK, 0 rows affected (0.01 sec)
mysql> set collation_server=utf8;
Query OK, 0 rows affected (0.01 sec)
查看:
mysql> show variables like 'character_set_%';

utf8 改为 gb2312

重启mysql :
如何启动/停止/重启MySQL

启动、停止、重启 MySQL 是每个拥有独立主机的站长必须要撑握的操作，下面为大家简单介绍一下操作方法：

一、启动方式

1、使用 service 启动：service mysqld start
2、使用 mysqld 脚本启动：/etc/inint.d/mysqld start
3、使用 safe_mysqld 启动：safe_mysqld&

二、停止

1、使用 service 启动：service mysqld stop
2、使用 mysqld 脚本启动：/etc/inint.d/mysqld stop
3、mysqladmin shutdown

三、重启

1、使用 service 启动：service mysqld restart
2、使用 mysqld 脚本启动：/etc/inint.d/mysqld restart

终极方法

mysql> set names gbk;

部分原文：http://blog.csdn.net/wyzxg/article/details/7581415

转载于:https://www.cnblogs.com/MYSQLZOUQI/p/3780967.html