安装MySQL

安装yum源：
wget http://repo.mysql.com/mysql57-community-release-el7-11.noarch.rpm
rpm -ivh mysql57-community-release-el7-11.noarch.rpm

安装：yum install mysql-server
启动：systemctl start mysqld
查看随机密码：cat /var/log/mysqld.log | grep password
A temporary password is generated for root@localhost: XH!QOs8w&tf2
使用随机密码登录：
mysql -u root -p
修改密码：
alter user 'root'@'localhost' identified by '123456';
报错：ERROR 1819 (HY000): Your password does not satisfy the current policy requirements
set global validate_password_policy=0;
set global validate_password_length=6;
alter user 'root'@'localhost' identified by '123456';
exit;

开放3306端口：
firewall-cmd --add-port=3306/tcp --permanent
firewall-cmd --reload

Navicat连接报错：1130-Host '192.168.3.115' is not allowed to connect to this MySQL server
grant all privileges on *.* to root@"%" identified by "123456";
flush privileges;
exit;