1 安装mysql

    yum install mysql

2 启动 mysql

    service mysql start

    centos 7之后的虚拟机需要使用 service mariadb start 

3 修改root默认密码 并给远程root访问添加权限    

[root@localhost ~]# mysql -uroot -p
Enter password: 
Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MariaDB connection id is 22
Server version: 5.5.56-MariaDB MariaDB Server


Copyright (c) 2000, 2017, Oracle, MariaDB Corporation Ab and others.


Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.


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 user set password=password('123456') where user='root';
Query OK, 5 rows affected (0.00 sec)
Rows matched: 5  Changed: 5  Warnings: 0


MariaDB [mysql]> flush privileges;
Query OK, 0 rows affected (0.00 sec)


MariaDB [mysql]> Ctrl-C -- exit!
Aborted
[root@localhost ~]# mysql -u root -p
Enter password: 
Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MariaDB connection id is 23
Server version: 5.5.56-MariaDB MariaDB Server


Copyright (c) 2000, 2017, Oracle, MariaDB Corporation Ab and others.


Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.


MariaDB [(none)]> grant all privileges on *.* to 'root'@'mysql服务器ip' identified by '123456' with grant option;
Query OK, 0 rows affected (0.00 sec)


MariaDB [(none)]> flush privileges;
Query OK, 0 rows affected (0.00 sec)


MariaDB [(none)]> exit;
Bye
[root@localhost ~]