MySQL字符集

------------------- ------------- Linux系统字符集编码 ------------------------------ ------------------

#1.命令行临时修改 : 
LANG=us_EN.UTF-8
LANG=zh_CN.UTF-8
 
临时修改报错命令为应文 : LANG=us_EN.UTF-8

#2.修改系统字符集
  Centos6 永久修改：[root@localhost ~]# vim /etc/sysconfig/i18n
  Centos7 永久修改：[root@localhost ~]# vim /etc/locale.conf


--------- ---------------- -----------   MySQL  --------------- ------------------------ -----------

编译之前指定
cmake .
-DDEFAULT_CHARSET=UTF8 -DDEFAULT_COLLATION=UTF8_GENERAL_CI
配置文件指定

#1.修改配置文件
[mysqld]
character-set-server=utf8
collation-server=utf8_general_ci
 
[client]
default-character-set=utf8
[mysql]
default-character-set=utf8
 
#2. 重启服务

#3. 查看修改结果：
mysql> show variables like ‘%char%‘;
+--------------------------+----------------------------+
| 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 (0.07 sec)


校验规则: utf8_general_ci
  1）ci：大小写不敏感
  2）cs或bin：大小写敏感
 
#一个表里面不可能出现同名不同大小写的字段
 
#查看校验规则
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 |
.........


utf8和utf8mb4之间的区别？
  utf8不支持emoji表情而utf8mb4支持。
通过SQL语句指定字符集编码

#创建数据库指定字符集和校验规则
create database db1 charset utf8mb4 collate utf8mb4_general_ci;

MySQL字符集

原文：https://www.cnblogs.com/backz/p/15349607.html