mysql 版本5.7.27
1下载mysql源安装包
wget http://dev.mysql.com/get/mysql57-community-release-el7-8.noarch.rpm
2.安装mysql源
yum localinstall mysql57-community-release-el7-8.noarch.rpm
3.检查mysql源是否安装成功
yum repolist enabled | grep "mysql.*-community.*"
4.安装mysql
yum install mysql-community-server
5.启动mysql
systemctl start mysqld
6.查看mysql状态
systemctl status mysqld
7.开机启动
systemctl enable mysqld
systemctl daemon-reload
8.获取mysql初始密码
grep 'temporary password' /var/log/mysqld.log
9.修改mysql密码
set password for 'root'@'localhost'=password('password')
10.查看mysql是否启动 service mysqld status
可以修改vim /etc/yum.repos.d/mysql-community.repo源，改变默认安装的mysql版本。比如要安装5.6版本，将5.7源的enabled=1改成enabled=0。然后再将5.6源的enabled=0改成enabled=1即可。改完之后的效果如下所示：
