卸载旧版本
$ sudo apt autoremove mariadb-* mysql-*
安装MariaDB
$ sudo apt install mariadb-server mariadb-client
修改配置文件
$ sudo vi /etc/mysql/mariadb.conf.d/50-server.cnf
在 [mysqld] 下增加增加一行 skip-grant-tables ，允许无密码进入 mysql ，并重启服务。
$ sudo service mysql restart
修改root用户密码
$ mysql -u root -p
直接回车即可，接下来修改 mysql 下的 root 用户密码
MariaDB [(none)]> use mysql;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
MariaDB [mysql]> update mysql.user set authentication_string=password('123456') where user='root';
Query OK, 1 row affected (0.00 sec)
Rows matched: 2 Changed: 1 Warnings: 0
MariaDB [mysql]> flush privileges;
Query OK, 0 rows affected (0.00 sec)
允许远程登录
修改配置文件
/etc/mysql/mariadb.conf.d/50-server.cnf，修改服务绑定的ip地址，修改完重启数据库。更新数据库
MariaDB [(none)]> use mysql;
MariaDB [(none)]> grant all privileges on *.* to 'root'@'%' identified by '123456' with grant option;
MariaDB [(none)]> flush privileges;
重启数据库
$ sudo service mysql restart
查看数据库使用字符集
MariaDB [(none)]> show variables like 'char%';
+--------------------------+----------------------------+
| Variable_name | Value |
+--------------------------+----------------------------+
| character_set_client | utf8mb4 |
| character_set_connection | utf8mb4 |
| character_set_database | utf8mb4 |
| character_set_filesystem | binary |
| character_set_results | utf8mb4 |
| character_set_server | utf8mb4 |
| character_set_system | utf8 |
| character_sets_dir | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+
8 rows in set (0.00 sec)
若出现 character_set_database 和 character_set_server 为latin1字符集，可修改 /etc/mysql/mariadb.conf.d/50-server.cnf，在 [mysql] 下增加一行 character-set-server=utf8。
