授权远程访问mysql超级用户远程访问：

mysql -u root -p
#输入密码，进入mysql客户
use mysql
GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY 'root password...' WITH GRANT OPTION;
FLUSH PRIVILEGES; #更新权限

忘记重设mysql 的root密码：

vim /etc/my.cnf
[mysqld] 
datadir=/var/lib/mysql  
socket=/var/lib/mysql/mysql.sock  
skip-grant-tables #添加这行
＃保存退出

systemctl restart mysqld
mysql -u root
use mysql;
#MySQL 5.7.6 以及最新版本：
update user set authentication_string=PASSWORD('new password') where User='root';
#MySQL 5.7.5 或更早之前的版本:
update user set password=PASSWORD('new password') where User='root';

Mysql5.7的运行SQL语句文件的时候会报下面错误：

 of ORDER BY clause is not in GROUP BY clause and contains nonaggregated c

解决方法：

在 /etc/my.cnf 文件里加上如下：
sql_mode='NO_ENGINE_SUBSTITUTION'
重启Mysql服务

mariadb安装：

mariadb安装：
yum install mariadb-server mariadb

mariadb数据库的相关命令是：
systemctl start mariadb  #启动MariaDB
systemctl stop mariadb  #停止MariaDB
systemctl restart mariadb  #重启MariaDB
systemctl enable mariadb  #设置开机启动

初始化：
mysql_secure_installation

mariadb配置允许远程访问方式：
mysql -u root -p
GRANT ALL PRIVILEGES ON *.* TO 'root'@'%'IDENTIFIED BY '20161130' WITH GRANT OPTION;
flush privileges;