Mysql - Mysql设置字符编码和修改字符编码（数据库，表，字段）

MySQL 的字符集支持(Character Set Support)有两个方面：字符集(Character set)和排序方式(Collation)。对于字符集的支持细化到四个层次: 服务器(server)，数据库(database)，数据表(table)和连接(connection)。

查看系统的字符集和排序方式的设定可以通过下面的两条命令或mysql> status 。

mysql> SHOW VARIABLES LIKE 'character_set_%'; 
+--------------------------+----------------------------+ 
| Variable_name | Value | 
+--------------------------+----------------------------+ 
| character_set_client | latin1 | 
| character_set_connection | latin1 | 
| character_set_database | latin1 | 
| character_set_results | latin1 | 
| character_set_server | latin1 | 
| character_set_system | utf8 | 
| character_sets_dir | /usr/share/mysql/charsets/ | 
+--------------------------+----------------------------+ 
7 rows in set (0.00 sec) 

mysql> SHOW VARIABLES LIKE 'collation_%'; 
+----------------------+-------------------+ 
| Variable_name | Value | 
+----------------------+-------------------+ 
| collation_connection | latin1_swedish_ci | 
| collation_database | latin1_swedish_ci | 
| collation_server | latin1_swedish_ci | 
+----------------------+-------------------+ 
3 rows in set (0.00 sec)

上面列出的值就是系统的默认值。(很奇怪系统怎么默认是latin1的瑞典语排序方式)... 

  当我们按照原来的方式通过PHP存取MySQL数据库时，就算设置了表的默认字符集为utf8并且通过UTF-8编码发送查询，你会发现存入数据库的仍然是乱码。问题就出在这个connection连接层上。解决方法是在发送查询前执行一下下面这句：

1. SET NAMES ‘utf8’;
   它相当于下面的三句指令：

SET character_set_client = utf8; 
SET character_set_results = utf8; 
SET character_set_connection = utf8;

1. 创建数据库

mysql> create database name character set utf8;

1. 创建表

CREATE TABLE `type` ( 
`id` int(10) unsigned NOT NULL auto_increment, 
`flag_deleted` enum('Y','N') character set utf8 NOT NULL default 'N', 
`flag_type` int(5) NOT NULL default '0', 
`type_name` varchar(50) character set utf8 NOT NULL default '', 
PRIMARY KEY (`id`) 
)  DEFAULT CHARSET=utf8;

1. 修改数据库成utf8的.

mysql> alter database name character set utf8;

1. 修改表默认用utf8.

mysql> alter table type character set utf8;

1. 修改字段用utf8

mysql> alter table type modify type_name varchar(50) CHARACTER SET utf8;