CentOS8安装MySQL5.7

不想使用MySQL8，只想使用MySQL5.7，可以按照以下方法安装。

禁用默认的MySQL源

sudo dnf remove @mysql
sudo dnf module reset mysql
sudo dnf module disable mysql

创建MySQL5.7的源文件

sudo vi /etc/yum.repos.d/mysql-community.repo

文件内容如下：

[mysql57-community]
name=MySQL 5.7 Community Server
baseurl=http://repo.mysql.com/yum/mysql-5.7-community/el/7/$basearch/
enabled=1
gpgcheck=0

[mysql-connectors-community]
name=MySQL Connectors Community
baseurl=http://repo.mysql.com/yum/mysql-connectors-community/el/7/$basearch/
enabled=1
gpgcheck=0

[mysql-tools-community]
name=MySQL Tools Community
baseurl=http://repo.mysql.com/yum/mysql-tools-community/el/7/$basearch/
enabled=1
gpgcheck=0

禁用MySQL8安装源

sudo dnf config-manager --disable mysql80-community

启用MySQL5.7安装源

sudo dnf config-manager --enable mysql57-community

安装MySQL5.7

sudo dnf install mysql-community-server

查看MySQL安装版本信息

rpm -qi mysql-community-server

设置开机启动MySQL

sudo systemctl enable --now mysqld.service

获得当前MySQL临时登录密码

sudo grep 'A temporary password' /var/log/mysqld.log |tail -1

执行安全安装并且修改MySQL密码

sudo mysql_secure_installation

用新密码登录到MySQL

mysql -u root -p