临时创建的一个测试库，忘记了root密码，用如下办法可以解决： 一、通过编辑/etc/my.cnf文件在[mysqld]下面加上skip-grant-tables=1,保存退出；
[mysqld] skip-grant-tables=1
二、重启MySql服务
[root@iZ2ze7qh6q0di3qkvef1dzZ etc]# systemctl stop mysqld.service [root@iZ2ze7qh6q0di3qkvef1dzZ etc]# systemctl start mysqld.service
三、以root身份登录mysql
[root@iZ2ze7qh6q0di3qkvef1dzZ etc]# mysql -u root Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 2 Server version: 5.7.24 MySQL Community Server (GPL) Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
四、进入mysql数据库
mysql> use mysql Reading table information for completion of table and column names You can turn off this feature to get a quicker startup with -A Database changed
五、修改root密码：
mysql> update user set authentication_string = password('HecomDB2015!@#'),password_last_changed=now() where user='root';
Query OK, 2 rows affected, 1 warning (0.00 sec)
Rows matched: 2 Changed: 2 Warnings: 1
六、退出mysql,再次编辑/etc/my.cnf文件，将第一步中添加的skip-grant-tables=1删掉，重启启动MySql服务即可。
