1）我们拿到一个新的centos系统是先安装 ；

yum install -y wget

2）然后安装wget http://dev.mysql.com/get/mysql-community-release-el7-5.noarch.rpm （这里我们安装的是mysql7.5）

wget  http://dev.mysql.com/get/mysql-community-release-el7-5.noarch.rpm 

3）然后执行rpm -Uvh mysql-community-release-el7-5.noarch.rpm 安装完成后

rpm -Uvh mysql-community-release-el7-5.noarch.rpm 

4）然后启动 systemctl start mysqld

 systemctl start mysqld 

5）然后查看状态systemctl ststus mysqld

systemctl ststus mysqld

6）执行 mysql -uroot 进入mysql当中

mysql -uroot 

7）执行 use mysql

 use mysql

8）然后配置用户和密码update user set password=password('root') where user='root';

update user set password=password('root') where user='root'

9）授权GRANT ALL PRIVILEGES ON . TO 'root'@'%' IDENTIFIED BY 'root';

GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY 'root'

10）然后跟新数据库flush privileges

flush privileges