创建用户：create user 'oracle'@'localhost' identified by 'password';

MySQL 8以上：alter user 'root'@'localhost' identified with mysql_native_password by 'newpassword';

MySQL 8以下版本: 1.set password for 'root'@'localhost' password('newpassword');

　　　　　　　　   2.update user set password="newpassword" where user="root";

                               3.mysqladmin -uroot -ppassword password newpassword;