linux（redhat | centos）安装mysql5.7
1、首先先卸载已安装的mysql
先停掉mysql服务
# service mysql status
MySQL running (25673)[ OK ]
# service mysql stop
Shutting down MySQL..[ OK ]
# service mysql status
MySQL is not running[FAILED]https://blog.csdn.net/wuwang0823/article/details/80171579
2、然后安装mysql
https://blog.csdn.net/weixin_42240930/article/details/83987496
3、首次登录修改默认密码
https://blog.csdn.net/jichuang123/article/details/62224187
补充知识：快速查看默认密码的命令
grep "temporary password" /var/log/mysqld.log
修改密码的3个方法：
https://blog.csdn.net/xuheng8600/article/details/80034647
4、设置远程访问
mysql默认是root@localhost访问，我要改为root@% 。 %代表任意ip ，与like用法一样
