環(huán)境

centos 7.x
MySQL 5.7.20

前提

• 1.MySQL 可以重啟
• 2.可以登錄服務器

操作

• 1.原密碼

[root@1]# mysql -uroot -p12345
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 4
Server version: 5.7.20-log MySQL Community Server (GPL)

Copyright (c) 2000, 2017, 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.

(root@localhost) [(none)]>

• 2.假設密碼忘記

- 1.配置 my.cnf
vim /etc/my.cnf // 注意每個配置文件不一定位置相同
[mysqld]
skip-grant-tables // 寫入 my.cnf 配置文件

- 2.重啟 MySQL
service mysqld restart // 重啟數據庫方法根據實際情況決定
Shutting down MySQL.. SUCCESS!
Starting MySQL... SUCCESS!

• 3.修改密碼

[root@1]# mysql // 以上做完之后，可以直接登錄
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.7.20-log MySQL Community Server (GPL)

Copyright (c) 2000, 2017, 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.

(root@localhost) [(none)]> alter user 'root'@'localhost' identified by '123'; // 這時由于系統(tǒng)檢測 skip grant，是不會讓你修改密碼的。
ERROR 1290 (HY000): The MySQL server is running with the --skip-grant-tables option so it cannot execute this statement

(root@localhost) [(none)]>flush PRIVILEGES; // 再次讓密碼生效
Query OK, 0 rows affected (0.01 sec)

(root@localhost) [(none)]>alter user 'root'@'localhost' identified by '123'; // 修改密碼
Query OK, 0 rows affected (0.00 sec)

(root@localhost) [(none)]>flush tables; // 刷內存數據
Query OK, 0 rows affected (0.00 sec)

(root@localhost) [(none)]>quit // 退出
Bye

• 4.成功現(xiàn)象

[root@1]# mysql // 密碼生效，skip grant 失效
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)

[root@1]# mysql -uroot -p123 // 這時使用密碼登錄，就可以正常使用了
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 4
Server version: 5.7.20-log MySQL Community Server (GPL)

Copyright (c) 2000, 2017, 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.

(root@localhost) [(none)]>

注意：記得把配置文件中 skip grant 注釋掉