1.MySQL编码集
查看MySQL支持的字符集
mysql> show character set;
查看MySQL当前的字符集
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)
或者使用status命令或者\s命令
上面的字符集是MySQL5.7.x安装好默认的字符集
命令的官网解释:
2.修改字符集
临时修改
-- set [global] variable_name=charset;
mysql> set global character_set_server=utf8;
永久修改
在my.cnf文件中指定
[client]
default-character-set=utf8
影响参数:
character_set_client
character_set_connection
character_set_results
[mysqld]
character-set-server=utf8
影响参数:
character_set_database
character_set_server
3.MySQL数据库中字符集转换流程
MySQL收到请求时将请求数据从character_set_client转换为character_set_connection
进行内部操作前将请求数据从character_set_connection转换为内部操作字符集,其确定方法如下
使用每个数据字段的CHARACTER SET设定值
若上述值不存在,则使用对应数据表的DEFAULT CHARACTER SET设定值(MySQL扩展,非SQL标准)
若上述值不存在,则使用对应数据库的DEFAULT CHARACTER SET设定值
若上述值不存在,则使用character_set_server设定值
将操作结果从内部操作字符集转换为character_set_connection
将响应数据从character_set_connection转为character_set_client
执行SQL语句时信息的路径是这样的
信息输入路径:client → connection → server;
信息输出路径:server → connection → results.
4.修改现有字符集
修改数据库的字符集
-- alter database db_name character set charset;
mysql> alter database snail character set utf8;
修改表的字符集
-- alter database table_name character set charset;
mysql> alter table people character set utf8;
修改列的字符集
-- alter table table_name change column_name column_name varchar(10) character set charset;
mysql> alter table people change name name varchar(10) character set utf8;