1.下載YUM庫

shell > wget http://dev.MySQL.com/get/mysql57-community-release-el7-7.noarch.rpm

2.安裝YUM庫

shell > yum localinstall -y mysql57-community-release-el7-7.noarch.rpm

3.安裝數據庫

shell > yum install -y mysql-community-server

4.啟動MySQL服務

shell > systemctl start mysqld.service

5.默認空密碼

shell > mysql -uroot -p

6.開啟mysql安全模式（重要！這里跟百度出來其他開啟安全模式方法不一樣）

修改my.cnf,添加skip-grant-tables和skip-networking

輸入：vi /etc/my.cnf

[mysqld]

skip-grant-tables

skip-networking

重啟mysql  然后輸入： mysql -uroot mysql 此時即可登錄mysql 

然后：update mysql.user set authentication_string=password("root123") where user="root" and Host="localhost";

flush PRivileges;

  quit;

重啟mysql后添加遠程登錄用戶(登入Mysql)：

GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY 'root123' WITH GRANT OPTION;

此時提示：The MySQL server is running with the --skip-grant-tables option so it cannot execute this statement

意思是要修改密碼，原來忘記修改my.cnf 退出安全模式

輸入：vi /etc/my.cnf   刪除

skip-grant-tables

skip-networking

執行下列操作：set global validate_password_policy=0;

set global validate_password_mixed_case_count=0;

set global validate_password_number_count=3;

set global validate_password_length=3;

然后更改密碼即可