ubuntu16.04 完全卸载MySQL

sudo apt-get autoremove --purge mysql-server-5.7 
#sudo apt-get remove mysql-server         # 没用到,已经没有mysql-server
#sudo apt-get autoremove mysql-server  # 没用到,已经没有mysql-server
sudo apt-get remove mysql-common
sudo rm -rf /etc/mysql/  /var/lib/mysql    #很重要
#清理残留数据
dpkg -l |grep ^rc|awk '{print $2}' |sudo xargs dpkg -P  
sudo apt autoremove
sudo apt autoreclean

安装MySQL:

sudo apt-get install mysql-server
sudo apt-get install mysql-client
sudo apt-get install libmysqlclient-dev

启动、关闭服务和查看运行状态

sudo service mysql start
sudo service mysql stop
sudo service mysql status