忘记mysql或mariadb数据库的密码之解决方案

一、实验环境

CentOS Linux release 7.5.1804 (Core)

mysql  Ver 15.1 Distrib 5.5.56-MariaDB, for Linux (x86_64) using readline 5.1

二、实施方案

第一步：添加--skip-grant-tables

在/etc/my.cnf.d/server.cnf中[mysqld]下面添加选项

[mysqld]
skip-grant-tables

第二步：重启数据库

[root@ken ~]# systemctl restart mariadb

第三步：登录数据库

现在发现可以在不输入密码的情况下直接登录进数据库

[root@ken ~]# mysql -uroot
Welcome to the MariaDB monitor.  Commands end with ; or g.
Your MariaDB connection id is 2
Server version: 5.5.56-MariaDB MariaDB Server

Copyright (c) 2000, 2017, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or 'h' for help. Type 'c' to clear the current input statement.

MariaDB [(none)]> 

第四步：修改密码

这个时候使用grant修改密码会报如下的错误

MariaDB [(none)]> grant all on *.* to root@'localhost' identified by '123';
ERROR 1290 (HY000): The MariaDB server is running with the --skip-grant-tables option so it cannot execute this statement

使用set修改密码也会报同样的错误

MariaDB [(none)]> set password for root@localhost=password('123');
ERROR 1290 (HY000): The MariaDB server is running with the --skip-grant-tables option so it cannot execute this statement

现在使用update即可进行修改

MariaDB [(none)]> use mysql;   #切换至mysql数据库
Database changed

MariaDB [mysql]> update user set password=password('123') where user='root';
Query OK, 3 rows affected (0.00 sec)
Rows matched: 4  Changed: 3  Warnings: 0

第五步：注销掉配置文件中的选项

[root@ken ~]# vim /etc/my.cnf.d/server.cnf
...
[mysqld]
#skip-grant-tables

第六步：重启数据库

[root@ken ~]# systemctl restart mariadb

第七步：再次登录进行验证

现在不输入密码被直接拒绝

[root@ken ~]# mysql -uroot
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)

输入密码123即可进行登录

[root@ken ~]# mysql -uroot -p123
Welcome to the MariaDB monitor.  Commands end with ; or g.
Your MariaDB connection id is 3
Server version: 5.5.56-MariaDB MariaDB Server

Copyright (c) 2000, 2017, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or 'h' for help. Type 'c' to clear the current input statement.

MariaDB [(none)]>