MySQL 体系结构
前言
本环境是基于 Centos 7.8 系统构建MySQL-5.7.14
具体构建，请参考 MySQL-5.7.14 环境构建
MySQL字符集包括字符集(CHARACTER）和校对规则(COLLATION)两个概念:
查看MySQL字符集
mysql> show variables like 'character%';
+--------------------------+----------------------------+
| Variable_name | Value |
+--------------------------+----------------------------+
| character_set_client | utf8 |
| character_set_connection | utf8 |
| character_set_database | latin1 |
| character_set_filesystem | binary |
| character_set_results | utf8 |
| character_set_server | latin1 |
| character_set_system | utf8 |
| character_sets_dir | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+
8 rows in set (0.00 sec)
查看MySQL字符校对规则
mysql> show collation;
+--------------------------+----------+-----+---------+----------+---------+
| Collation | Charset | Id | Default | Compiled | Sortlen |
+--------------------------+----------+-----+---------+----------+---------+
| big5_chinese_ci | big5 | 1 | Yes | Yes | 1 |
| big5_bin | big5 | 84 | | Yes | 1 |
| dec8_swedish_ci | dec8 | 3 | Yes | Yes | 1 |
| dec8_bin | dec8 | 69 | | Yes | 1 |
| cp850_general_ci | cp850 | 4 | Yes | Yes | 1 |
| cp850_bin | cp850 | 80 | | Yes | 1 |
| hp8_english_ci | hp8 | 6 | Yes | Yes | 1 |
| hp8_bin | hp8 | 72 | | Yes | 1 |
| koi8r_general_ci | koi8r | 7 | Yes | Yes | 1 |
| koi8r_bin | koi8r | 74 | | Yes | 1 |
| latin1_german1_ci | latin1 | 5 | | Yes | 1 |
| latin1_swedish_ci | latin1 | 8 | Yes | Yes | 1 |
... ...
一、MySQL 字符集命名后缀名有哪些？代表什么含义？
MySQL字符序命名规则是:以字符序对应的字符集名称开头，以国家名居中(或以general居中)，以ci、cs或bin结尾。
- ci：表示大小写不敏感
- cs：表示大小写敏感
- bin 表示按二进制编码值比较
二、修改MySQL字符集
我们通过修改MySQL服务的配置文件，修改数据库的字符集，全局生效
查看当前数据库的字符集
mysql> show variables like '%character%';
+--------------------------+----------------------------+
| Variable_name | Value |
+--------------------------+----------------------------+
| character_set_client | utf8 |
| character_set_connection | utf8 |
| character_set_database | latin1 |
| character_set_filesystem | binary |
| character_set_results | utf8 |
| character_set_server | latin1 |
| character_set_system | utf8 |
| character_sets_dir | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+
8 rows in set (0.00 sec)
修改数据库字符集
#配置文件中添加设置内容
[root@mysql-server ~]# vim /etc/my.cnf
[mysqld]
character-set-server=utf8
[client]
default-character-set=utf8
退出数据库，重新登录，再次查看数据库的字符集
mysql> show variables like '%character%';
+--------------------------+----------------------------+
| Variable_name | Value |
+--------------------------+----------------------------+
| character_set_client | utf8 |
| character_set_connection | utf8 |
| character_set_database | utf8 |
| character_set_filesystem | binary |
| character_set_results | utf8 |
| character_set_server | utf8 |
| character_set_system | utf8 |
| character_sets_dir | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+
8 rows in set (0.00 sec)
注：character_set_filesystem 默认字符集为binary，为固定设置，不可修改