一、停止MySQL
[root@localhost /]# service mysqld stop
二、查看当前安装mysql情况，查找以前是否装有mysql
[root@localhost /]# rpm -qa|grep -i mysql
mysql-community-client-8.0.13-1.el7.x86_64
mysql-community-libs-8.0.13-1.el7.x86_64
mysql-community-common-8.0.13-1.el7.x86_64
mysql-community-server-8.0.13-1.el7.x86_64
三、执行命令删除安装的MySQL
[root@localhost /]# rpm -ev mysql-community-client-8.0.13-1.el7.x86_64
报错：
error: Failed dependencies:
mysql-community-client(x86-64) >= 8.0.0 is needed by (installed) mysql-community-server-8.0.13-1.el7.x86_64
原因是依赖包错误，再执行以下命令解决：
[root@localhost /]# rpm -ev mysql-community-client-8.0.13-1.el7.x86_64 --nodeps
剩余几个也按照上述操作执行，加上 --nodeps
再执行 # rpm -qa|grep -i mysql 命令，查看是否删除成功。
四：查看之前安装的MySQL的目录并删除
[root@localhost /]# find / -name mysql
/var/lib/mysql
/var/lib/mysql/mysql
/usr/lib64/mysql
/usr/share/mysql
[root@localhost /]# rm -rf /var/lib/mysql
[root@localhost /]# rm -rf /var/lib/mysql/mysql
[root@localhost /]# rm -rf /usr/lib64/mysql
[root@localhost /]# rm -rf /usr/share/mysql
五：删除my.cnf
卸载后/etc/my.cnf不会删除，需要进行手工删除
[root@localhost /]# rm -rf /etc/my.cnf
最后查看一下是否卸载完毕，无结果说明卸载完成。
[root@localhost /]# rpm -qa|grep -i mysql
