yum卸载

1、查看mysql安装了哪些东西

rpm -qa |grep -i mysql

2、开始卸载

yum remove mysql-community-common-5.7.20-1.el7.x86_64
yum remove mysql-community-client-5.7.20-1.el7.x86_64
yum remove mysql57-community-release-el7-11.noarch
yum remove mysql-community-libs-5.7.20-1.el7.x86_64
yum removemysql-community-server-5.7.20-1.el7.x86_64
...

3.查看是否卸载完成

rpm -qa |grep -i mysql

4.删除相关目录

find / -name mysql
rm -rf

5.删除/var/log/mysqld.log

如果不删除这个文件，会导致新安装的mysql无法生存新密码，导致无法登陆