1、首先把自己的账户切换到root账户

[root@localhost ~]# su root 

下面跟上自己的密码，密码直接输入即可是不显示的，输入完成之后按回车

2、检查一下自己电脑上安装了哪些mysql

[root@localhost ~]# find / -name mysql

3、把安装的mysql全部删掉

[root@localhost ~]# rm -rf /usr/lib64/mysql/
[root@localhost ~]# rm -rf /usr/local/mysql/
[root@localhost ~]# rm -rf /etc/selinux/targeted/active/modules/100/mysql/

3、查看自己的包卸载完成没有
[root@localhost ~]# find / -name mysql
find: ‘/run/user/1000/gvfs’: Permission denied

4、如果需要下载最新包请去官网下载，下载地址：MySQL :: Download MySQL Community Server (Archived Versions)  （已经下载好了的，可以省略这一步）

 5、下载安装包，若不想去官网下载，直接使用下面这个地址的包也是可以的。

[root@localhost ~]# cd /usr/local/

[root@localhost ~]# wget https://cdn.mysql.com//Downloads/MySQL-8.0/mysql-8.0.32-1.el7.x86_64.rpm-bundle.tar

 6、查看和删除centos自带mariadb安装包

#查看rpm -qa | grep mariadb

[root@localhost local]# rpm -qa | grep mariadb
mariadb-libs-5.5.68-1.el7.x86_64

#删除 rm -rf mariadb-libs-5.5.68-1.el7.x86_64

 [root@localhost local]# rm -rf mariadb-libs-5.5.68-1.el7.x86_64

[root@localhost local]# rpm -qa | grep mariadb 

7、解压

[root@localhost local]# tar xf mysql-8.0.32-1.el7.x86_64.rpm-bundle.tar 

#查看解压成功没
[root@localhost local]# ls -ll
解压成功如下所示

8、安装是有安装顺序的，请一定要按照我这个安装顺序安装，不然会报错，让你解决依赖关系。

1）安装：mysql-community-common-8.0.32-1.el7.x86_64.rpm

[root@localhost local]#  rpm -ivh mysql-community-common-8.0.32-1.el7.x86_64.rpm

 2）安装mysql-community-client-plugins-8.0.32-1.el7.x86_64.rpm

[root@localhost local]# rpm -ivh mysql-community-client-plugins-8.0.32-1.el7.x86_64.rpm 

3）安装rpm -ivh mysql-community-libs-8.0.32-1.el7.x86_64.rpm

[root@localhost local]# rpm -ivh mysql-community-libs-8.0.32-1.el7.x86_64.rpm

 4）安装rpm -ivh mysql-community-client-8.0.32-1.el7.x86_64.rpm

[root@localhost local]#  rpm -ivh mysql-community-client-8.0.32-1.el7.x86_64.rpm

5）安装 rpm -ivh mysql-community-icu-data-files-8.0.32-1.el7.x86_64.rpm

[root@localhost local]#  rpm -ivh mysql-community-icu-data-files-8.0.32-1.el7.x86_64.rpm 

6）安装rpm -ivh mysql-community-server-8.0.32-1.el7.x86_64.rpm

[root@localhost local]#  rpm -ivh mysql-community-server-8.0.32-1.el7.x86_64.rpm

9、然后执行一下下面的两个命令

[root@localhost local]# systemctl start mysqld
[root@localhost local]# systemctl status mysqld

 10、设置开机自启服务（需要的可以自行设置）

[root@localhost local]# systemctl enable mysqld
[root@localhost local]# 

 11、查看初始密码是多少，然后设置密码

#查看初始密码

[root@localhost local]# cat /var/log/mysqld.log | grep password

#登录

[root@localhost local]# mysql -u root -p
Enter password: 

12、修改初始密码

mysql> alter user 'root'@'localhost' identified by '您的密码';

希望对你有所帮助，谢谢~