apt-get install mysql-server 時候報錯如下：
Preconfiguring packages ...
Setting up mysql-common (5.7.13-0ubuntu0.16.04.2) ...
update-alternatives: error: alternative path /etc/mysql/my.cnf.fallback doesn't exist
dpkg: error processing package mysql-common (--configure):
subprocess installed post-installation script returned error exit status 2
Errors were encountered while processing:
mysql-common
E: Sub-process /usr/bin/dpkg returned an error code (1)
網上找到差不多的錯誤，於是決定嘗試下。good luck for me ！！ ok 了
解決辦法：
刪除mysql前 先刪除一下 /var/lib/mysql 還有 /etc/mysql
sudo rm /var/lib/mysql/ -R
sudo rm /etc/mysql/ -R
sudo apt-get autoremove mysql* --purge
sudo apt-get remove apparmor
sudo apt-get install mysql-server mysql-common
感謝這位博主：
原文地址：http://blog.sina.com.cn/s/blog_417ad82e0101el5i.html