mysql在线安装

下载mysql
wget https://dev.mysql.com/get/mysql80-community-release-el7-3.noarch.rpm

添加到本地：
yum localinstall mysql80-community-release-el7-3.noarch.rpm
正式安装：
yum install mysql-community-server --nogpgcheck
启动：
service mysqld start
service mysqld status
查看默认密码并登陆：
cat /var/log/mysqld.log | grep password
登陆：mysql -u root -p
Enter: 密码
修改密码：
ALTER USER ‘root’@‘localhost’ IDENTIFIED WITH mysql_native_password BY ‘xxx’
修改密码策略：
set global validate_password.policy=0;
set global validate_password.length=6;
修改成简单密码：
ALTER USER ‘root’@‘localhost’ IDENTIFIED WITH mysql_native_password BY ‘123456’;