[root@localhost~]# vi /etc/my.cnf  (如果不行则sudo vi /etc/my.cnf)

#在[mysqld]标签下添加

character-set-server=utf8

[root@localhost~]# vi /etc/my.cnf.d/client.cnf

#在[client]标签下添加

default-character-set=utf8

重启

[root@localhost~]# systemctl restart mariadb

mysql -u root -p 后查看现在的字符编码

show variables like '%character%';