一、卸载已安装的MySQL包

1、查找以下安装包

**使用命令   yum list installed | grep mysql**

[root@localhost7 ~]# yum list installed | grep mysql
mysql-community-client.x86_64         5.7.31-1.el7               @mysql57-community
mysql-community-common.x86_64         5.7.31-1.el7               @mysql57-community
mysql-community-libs.x86_64           5.7.31-1.el7               @mysql57-community
mysql-community-libs-compat.x86_64    5.7.31-1.el7               @mysql57-community
mysql-community-server.x86_64         5.7.31-1.el7               @mysql57-community
mysql57-community-release.noarch      el7-11                     @/mysql57-community-release-el7-11.noarch

**或者用以下命令查找   rpm -qa|grep mysql**

[root@localhost7 ~]# rpm -qa|grep mysql
mysql-community-server-5.7.31-1.el7.x86_64
mysql-community-common-5.7.31-1.el7.x86_64
mysql-community-client-5.7.31-1.el7.x86_64
mysql57-community-release-el7-11.noarch
mysql-community-libs-compat-5.7.31-1.el7.x86_64
mysql-community-libs-5.7.31-1.el7.x86_64

2、将前面的6个安装包都删除

[root@localhost7 ~]# yum remove xxxxxxx
 或者
[root@localhost7 ~]# rpm -e --nodeps xxxxxxx

xxxxx是前面的安装包名，--nodeps是强制删除。

3、查找mysql残留文件夹，并删除

[root@localhost7 ~]# find / -name mysql
/etc/logrotate.d/mysql
/var/lib/mysql
/var/lib/mysql/mysql
/usr/bin/mysql
/usr/lib64/mysql
/usr/share/mysql

 删除 (请勿删错，谨慎操作！)
 rm-rf xxxxxx