查看修改MySQL字符集

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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标签：  字符集   mysql数据库   mysql字符集查看   mysql启动命令   修改mysql字符集

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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。

1. mysql> show variables like '%char%';  
2. +--------------------------+-------------------------------------+------  
3. | Variable_name            | Value                               |......  
4. +--------------------------+-------------------------------------+------  
5. | character_set_client     | utf8                                |......   -- 客户端字符集  
6. | character_set_connection | utf8                                |......  
7. | character_set_database   | utf8                                |......   -- 数据库字符集  
8. | character_set_filesystem | binary                              |......  
9. | character_set_results    | utf8                                |......  
10. | character_set_server     | utf8                                |......   -- 服务器字符集  
11. | character_set_system     | utf8                                |......  
12. | character_sets_dir       | D:\MySQL Server 5.0\share\charsets\ |......  
13. +--------------------------+-------------------------------------+------ 

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> show variables like 'collation%'; +----------------------+-----------------+ | Variable_name        | Value           | +----------------------+-----------------+ | collation_connection | utf8_general_ci | | collation_database   | utf8_general_ci | | collation_server     | utf8_general_ci | +----------------------+-----------------+ 3 rows in set (0.00 sec)

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>

 

查看列的字符集 mysql> show full columns from t3; +-------+-------------+-------------------+------+-----+---------+-------+---------------------------------+---------+ | Field | Type        | Collation         | Null | Key | Default | Extra | Privileges                      | Comment | +-------+-------------+-------------------+------+-----+---------+-------+---------------------------------+---------+ | a1    | varchar(10) | utf8_general_ci   | YES  |     | NULL    |       | select,insert,update,references |         | | a2    | varchar(10) | latin1_swedish_ci | YES  |     | NULL    |       | select,insert,update,references |         | +-------+-------------+-------------------+------+-----+---------+-------+---------------------------------+---------+ 2 rows in set (0.01 sec)

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> show full columns from t3; +-------+-------------+-----------------+------+-----+---------+-------+---------------------------------+---------+ | Field | Type        | Collation       | Null | Key | Default | Extra | Privileges                      | Comment | +-------+-------------+-----------------+------+-----+---------+-------+---------------------------------+---------+ | a1    | varchar(10) | utf8_general_ci | YES  |     | NULL    |       | select,insert,update,references |         | | a2    | varchar(10) | utf8_general_ci | YES  |     | NULL    |       | select,insert,update,references |         | +-------+-------------+-----------------+------+-----+---------+-------+---------------------------------+---------+ 2 rows in set (0.00 sec)

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> show variables like 'storage%'; +----------------+--------+ | Variable_name  | Value  | +----------------+--------+ | storage_engine | MyISAM | +----------------+--------+ 1 row in set (0.01 sec)

mysql>

 

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

 

重启mysql服务，查看

mysql> show variables like 'storage%'; +----------------+--------+ | Variable_name  | Value  | +----------------+--------+ | storage_engine | InnoDB | +----------------+--------+ 1 row in set (0.01 sec)

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。

1. mysql> show table status from sqlstudy_db like '%countries%';  
2. +-----------+--------+---------+------------+------+-----------------+------  
3. | Name      | Engine | Version | Row_format | Rows | Collation       |......  
4. +-----------+--------+---------+------------+------+-----------------+------  
5. | countries | InnoDB |      10 | Compact    |   11 | utf8_general_ci |......  
6. +-----------+--------+---------+------------+------+-----------------+------ 

三、查看MySQL数据列（column）的MySQL字符集。

1. mysql> show full columns from countries;  
2. +----------------------+-------------+-----------------+--------  
3. | Field                | Type        | Collation       | .......  
4. +----------------------+-------------+-----------------+--------  
5. | countries_id         | int(11)     | NULL            | .......  
6. | countries_name       | varchar(64) | utf8_general_ci | .......  
7. | countries_iso_code_2 | char(2)     | utf8_general_ci | .......  
8. | countries_iso_code_3 | char(3)     | utf8_general_ci | .......  
9. | address_format_id    | int(11)     | NULL            | .......  
10. +----------------------+-------------+-----------------+-------- 

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