mysql enterperise企业版是收费的，mysql communite社区版是免费的。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-serversudo apt-get remove mysql-commonsudo 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 autoremovesudo apt autoreclean

root@ubuntu:/# service mysql status● mysql.service - MySQL Community Server   Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: enabled)   Active: active (running) since 日 2018-02-25 04:29:41 PST; 19min ago  Process: 1486 ExecStartPost=/usr/share/mysql/mysql-systemd-start post (code=exited, status=0/  Process: 1375 ExecStartPre=/usr/share/mysql/mysql-systemd-start pre (code=exited, status=0/SU Main PID: 1485 (mysqld)    Tasks: 28   Memory: 79.4M      CPU: 1.235s   CGroup: /system.slice/mysql.service           └─1485 /usr/sbin/mysqld2月 25 04:29:22 ubuntu systemd[1]: Starting MySQL Community Server...2月 25 04:29:41 ubuntu systemd[1]: Started MySQL Community Server.root@ubuntu:/# service mysql startroot@ubuntu:/# mysql -u root -pEnter password: