centos7下安装mysql5.7

1.下载YUM库

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

2.安装YUM库

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

3.安装数据库

shell > yum install -y mysql-community-server

4.启动MySQL服务

shell > systemctl start mysqld.service

5.默认空密码

shell > mysql -uroot -p

6.开启mysql安全模式（重要！这里跟百度出来其他开启安全模式方法不一样）

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

输入：vi /etc/my.cnf

[mysqld]

skip-grant-tables

skip-networking

重启mysql  然后输入： mysql -uroot mysql 此时即可登录mysql 

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

flush PRivileges;

  quit;

重启mysql后添加远程登录用户(登入Mysql)：

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

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

意思是要修改密码，原来忘记修改my.cnf 退出安全模式

输入：vi /etc/my.cnf   删除

skip-grant-tables

skip-networking

执行下列操作：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;

然后更改密码即可