[root@master ~]# rpm -qa | grep mariadb
mariadb-server-5.5.52-1.el7.x86_64
mariadb-libs-5.5.52-1.el7.x86_64
[root@localhost ~]# rpm -e mysql-*

[root@master ~]# yum remove mysql mysql-server mysql-libs compat-mysql51
已加载插件：fastestmirror, langpacks
参数 mysql 没有匹配
参数 mysql-server 没有匹配
参数 compat-mysql51 没有匹配
正在解决依赖关系
--> 正在检查事务
---> 软件包 mariadb-libs.x86_64.1.5.5.52-1.el7 将被 删除
--> 正在处理依赖关系 libmysqlclient.so.18()(64bit)，它被软件包 perl-DBD-MySQL-4.023-5.el7.x86_64 需要
--> 正在处理依赖关系 libmysqlclient.so.18()(64bit)，它被软件包 2:postfix-2.10.1-6.el7.x86_64 需要
--> 正在处理依赖关系 libmysqlclient.so.18()(64bit)，它被软件包 1:qt-mysql-4.8.5-13.el7.x86_64 需要..........
删除:
 mariadb-libs.x86_64 1:5.5.52-1.el7                      
作为依赖被删除:
 akonadi-mysql.x86_64 0:1.9.2-4.el7   mariadb-server.x86_64 1:5.5.52-1.el7  
 perl-DBD-MySQL.x86_64 0:4.023-5.el7  postfix.x86_64 2:2.10.1-6.el7     
 qt-mysql.x86_64 1:4.8.5-13.el7    
完毕！
[root@master ~]# rpm -qa|grep mariadb
[root@master ~]#

[root@master ~]# yum -y install MariaDB-server MariaDB-client
Loaded plugins: fastestmirror, langpacks
(1/7): epel/7/x86_64/updateinfo
 ...
(7/7): pgdg95/7/x86_64/primary_db
Loading mirror speeds from cached hostfile
Resolving Dependencies
--> Running transaction check
 ...
--> Finished Dependency Resolution
Dependencies Resolved
==============================================================================
 Package               Arch        Version
==============================================================================
Installing:
 MariaDB-client           x86_64       10.2.4-1.el7.centos
 MariaDB-server           x86_64       10.2.4-1.el7.centos
Installing for dependencies:
 MariaDB-common           x86_64       10.2.4-1.el7.centos
 MariaDB-compat           x86_64       
 ...
Transaction Summary
==============================================================================
Install 2 Packages (+12 Dependent packages)
Total size: 173 M
Total download size: 113 M
Installed size: 731 M
  ...

[root@master ~]# systemctl start mariadb
[root@master ~]# systemctl enable mariadb
[root@master ~]# systemctl restart mariadb
[root@master ~]# systemctl stop mariadb.service

[root@master ~]# mysql -uroot -p123456

[root@master etc]# cat /etc/my.cnf

init_connect='SET collation_connection = utf8_unicode_ci' 
init_connect='SET NAMES utf8' 
character-set-server=utf8 
collation-server=utf8_unicode_ci 
skip-character-set-client-handshake

  [root@master my.cnf.d]# mysql -uroot -p123456
  MariaDB [(none)]> show variables like "%character%";show variables like "%collation%";

MariaDB [(none)]> create user mariadb@localhost identified by '123456';
MariaDB [(none)]> grant all on *.* to mariadb@localhost identified by '123456';
MariaDB [(none)]> grant all privileges on *.* to mariadb@'%' identified by '123456';
MariaDB [(none)]> grant all privileges on *.* to mariadb@'master' identified by '123456' with grant option;
MariaDB [(none)]> use mysql;

MariaDB [mysql]> select host,user,password from user;

use mysql
update user set password=password(“new_pass”) where user=“root”;
flush privileges;
exit;