在一些非常规安装时会遇到这个莫名其妙的问题：OS是Ubuntu，MySQL版本是5.7.26。

安装后MySQL的error log提示：[Warning] root@localhost is created with an empty password ! Please consider switching off the --initialize-insecure option.

解决：

# sudo mysql -uroot

mysql> ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password;

mysql> alter user root@localhost identified with mysql_native_password as '*xxxxx';