参考链接:
https://blog.csdn.net/weixin_35782943/article/details/113330603

1、基础环境准备

  1. #卸载CentOS 7 自带MariaDB
  2. yum -y remove mariadb-libs
  4. #查看系统是否安装mysql
  5. rpm -qa | grep mysql
  7. id mysql
  8. useradd -s /sbin/nologin -M mysql
  10. #yum源安装会自动检测所需要的依赖,进行安装

2、安装 MySQL

https://dev.mysql.com/downloads/repo/yum/
选择对应的操作系统和版本
image.png
image.png

#下载yum源rpm安装包
wget https://dev.mysql.com/get/mysql80-community-release-el7-3.noarch.rpm

#校验MD5码
md5sum mysql80-community-release-el7-3.noarch.rpm

#安装yum源
rpm -ivh mysql80-community-release-el7-3.noarch.rpm

#安装完成会多出2个mysqlyum源文件
ls /etc/yum.repos.d/
mysql-community.repo  mysql-community-source.repo

#安装mysql(默认会安装mysql 8.0),需要其它版本参考第8步
yum -y install mysql-server

3、初始化 MySQ

mysqld --initialize --user=mysql

#查看初始化信息 和 生成的临时密码
密码在最后一行:
cat /var/log/mysqld.log

2021-06-11T08:28:14.786963Z 0 [System] [MY-013169] [Server] /usr/sbin/mysqld (mysqld 8.0.24) initializing of server in progress as process 2558
2021-06-11T08:28:14.913520Z 1 [System] [MY-013576] [InnoDB] InnoDB initialization has started.
2021-06-11T08:28:19.513218Z 1 [System] [MY-013577] [InnoDB] InnoDB initialization has ended.
2021-06-11T08:28:23.989009Z 6 [Note] [MY-010454] [Server] A temporary password is generated for root@localhost: ShukUrvu_3Ww

4、启动 MySQL

systemctl enable mysqld
systemctl start mysqld
systemctl status mysqld

5、登录 MySQL

#用生活层的临时密码登录,登录后需立即修改密码
mysql -uroot -p
Enter password: 输入初始化生成的临时密码
alter user 'root'@'localhost' identified by '123';
flush privileges;
mysql -uroot -p123

6、目录结构

yum源安装各版本 - 图3

7、卸载 MySQL

#停止mysql
systemctl stop mysqld
systemctl disable mysqld

#查看安装的mysql
yum list installed | grep mysql

#卸载mysql
yum -y remove mysql-community-*.x86_64

#删除mysql用户
userdel mysql

8、安装其它版本

#修改mysql,yum源文件
vim /etc/yum.repos.d/mysql-community.repo

#文件内容
[mysql57-community]
name=MySQL 5.7 Community Server
baseurl=http://repo.mysql.com/yum/mysql-5.7-community/el/7/$basearch/
enabled=0
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-mysql

[mysql80-community]
name=MySQL 8.0 Community Server
baseurl=http://repo.mysql.com/yum/mysql-8.0-community/el/7/$basearch/
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-mysql

#修改yum文件,需要那个版本,就在对应区域将enabled=0改为1,将原来的位置改为0
例如需要安装mysql5.7
[mysql80-community]
enabled=0

[mysql57-community]
enabled=1

#安装mysql
yum -y install mysql-server