同时按下键盘上的win徽标+R，选择cmd，回车键打开cmd，在命令行中输入mysql -u root -p
切记只有这句话“mysql -u root -p ” ，p后面没有分号“；”，否则就会报出以下错误，即提醒使用者不要在cmd命令行中输入密码，这种做法是不安全的。
正确示例：
C:\Users\hemiao>mysql -u root -pEnter password: ******Welcome to the MySQL monitor. Commands end with ; or \g.Your MySQL connection id is 6Server version: 5.7.17-log MySQL Community Server (GPL)Copyright (c) 2000, , Oracle and/or its affiliates. All rights reserved.Oracle is a registered trademark of Oracle Corporation and/or itsaffiliates. Other names may be trademarks of their respectiveowners.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
错误示例：
C:\Users\hemiao>mysql -u root -p;mysql: [Warning] Using a password on the command line interface can be insecure.ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)
