一、环境
OS信息：
LSB Version: :core-4.1-amd64:core-4.1-noarch:cxx-4.1-amd64:cxx-4.1-noarch:desktop-4.1-amd64:desktop-4.1-noarch:languages-4.1-amd64:languages-4.1-noarch:printing-4.1-amd64:printing-4.1-noarch
Distributor ID: CentOS
Description: CentOS Linux release 7.4.1708 (Core)
Release: 7.4.1708
Codename: Core
MySQL版本：5.7.20
二、步骤
配置Yum repository
从MySQL官网找到你要的库文件，获取链接，然后下载到本地
wget https://dev.mysql.com/get/mysql57-community-release-el7-11.noarch.rpm
添加repository命令
sudo yum localinstall mysql57-community-release-el7-11.noarch.rpm
检查是否配置成功
shell> yum repolist enabled | grep "mysql.*-community.*"
安装MySQL
shell> sudo yum install mysql-community-server
启动MySQL服务器
shell> sudo service mysqld start
shell> sudo service mysqld status
三、配置
修改密码
安装程序会自动创建一个超级用户'root'@'localhost，密码在错误日志里，可以用下面命令获得：
shell> sudo grep 'temporary password' /var/log/mysqld.log
利用刚才的密码登录：
shell> mysql -uroot -p
修改默认密码：
mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'password';
开启外部访问权限
此时，数据库仅能被本机访问，外部访问时会提示该主机不允许连接MySQL服务器：
ERROR 1130 (00000): Host 'xxx.xxx.xxx.xxx' is not allowed to connect to this MySQ
L server
原因是MySQL限制了现有用户只有localhost才能访问
mysql> select host, user from user;
+-----------+---------------+
| host | user |
+-----------+---------------+
| localhost | mysql.session |
| localhost | mysql.sys |
| localhost | root |
+-----------+---------------+
3 rows in set (0.00 sec)
解决方法是创建允许其它主机访问的用户或直接把root的host改成”%”（表示任何主机）
CREATE USER 'username'@'%' IDENTIFIED BY 'password';
update user set host = '%' where user = 'root';
flush privileges;
其它信息
/etc/my.cnf mysql的主配置文件
/var/lib/mysql mysql数据库文件存放位置
/var/log mysql日志输出存放目录