在*面centos7上部署MYSQL5.7数据库

1. 利用xshell连接好服务后，输入 wget http://dev.mysql.com/get/mysql57-community-release-el7-8.noarch.rpm 下载软件安装包文件

2. 输入 yum localinstall mysql57-community-release-el7-8.noarch.rpm 安装文件

3. 输入 yum repolist enabled | grep "mysql.*-community.*" 检查是否安装成功，出现如图表示成功

4. 输入 yum install mysql-community-server 安装服务，过程中会让你确认，一直输入 y 确认即可

5. 输入 systemctl start mysqld 启动数据库

6. 输入 systemctl enable mysqld 后，再输入 systemctl daemon-reload 设置开机启动

7. 输入 grep 'temporary password' /var/log/mysqld.log 得到临时密码，i?9hwo%fmidf 就是临时密码

a temporary password is generated for root@localhost: i?9hwo%fmidf

8. 输入 mysql -uroot -p 后输入密码，就是刚才的临时密码

9. 进入mysql，修改密码：输入 alter user 'root'@'localhost' identified by 'newpassword!'; 密码必须包含：大小写字母、数字和特殊符号，并且长度不能少于8位，否则会提示error 1819 (hy000): your password does not satisfy the current policy requirements错误