下载mysql57源

root@localhost ~]# wget http://dev.mysql.com/get/mysql57-community-release-el7-8.noarch.rpm

[root@localhost ~]# yum localinstall mysql57-community-release-el7-8.noarch.rpm

导入GPG秘钥（不导入GPG秘钥安装rpm包会报错）

[root@localhost ~]# rpm --import https://repo.mysql.com/RPM-GPG-KEY-mysql-2022

安装mysql

[root@localhost ~]# yum install mysql-community-server -y

启动mysql服务,设置为开机自启

[root@localhost ~]# systemctl start mysqld && systemctl enable mysqld

通过mysql日志中查看root初始化密码

[root@localhost ~]# cat /var/log/mysqld.log |grep pass

2023-07-04T06:14:58.837965Z 1 [Note] A temporary password is generated for root@localhost: L1YKylZ9

修改密码复杂性和密码长度（默认修改密码需要满足复杂性要求）

mysql> set global validate_password_policy=0;

Query OK, 0 rows affected (0.00 sec)

mysql> set global validate_password_length=1;

Query OK, 0 rows affected (0.00 sec)

登录mysql修改默认密码

mysql> alter user 'root'@localhost identified by 'test.123';