连接mysql时提示is not allowed to connect不允许连接

1. 进入mysql服务器，mysql -u root -p 登录myql服务，SELECT user, host FROM mysql.user;看到root只允许localhost本机连接

 2. 执行use mysql;    update user set host = '%' where user = 'root'; 再次查看user表，root允许所有ip连接

 3.刷新缓存FLUSH PRIVILEGES;