前提，

能登录到mysql的这台Linux服务器 ；

已经忘记了mysql root密码，无法登录的情况下，

限于有权限修改mysql安装文件（此方法适用于**linux **）

以Linux为例：

1.编辑/etc/my.cnf配置文件，vim /etc/my.cnf

2.在[mysqld]下添加一行 skip-grant-tables，然后保存并退出

[mysqld]

Remove leading # and set to the amount of RAM for the most important data

cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%.

innodb_buffer_pool_size = 128M

Remove leading # to turn on a very important data integrity option: logging

changes to the binary log between backups.

log_bin

Remove leading # to set options mainly useful for reporting servers.

The server defaults are faster for transactions and fast SELECTs.

Adjust sizes as needed, experiment to find the optimal values.

join_buffer_size = 128M

sort_buffer_size = 2M

read_rnd_buffer_size = 2M

datadir=/var/lib/mysql

socket=/var/lib/mysql/mysql.sock

Disabling symbolic-links is recommended to prevent assorted security risks

symbolic-links=0

log-error=/var/log/mysqld.log

pid-file=/var/run/mysqld/mysqld.pid

ADD free password by idoxu (isTester.com)

skip-grant-tables # IDO老徐注：新增这行

~

~

3.重启mysql服务：service mysqld restart

[root@isTester ~]# service mysqld restart

Redirecting to /bin/systemctl restart mysqld.service

[root@isTester ~]**# **

4.更改root密码

重启以后，执行mysql命令进入mysql命令行（上面已经设置了跳过密码，不用输入密码）

[root@isTester ~]# mysql

Welcome to the MySQL monitor. Commands end with ; or \g.

Your MySQL connection id is 2

Server version: 5.7.30 MySQL Community Server (GPL)

Copyright (c) 2000, 2020, 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.

mysql>

5.修改root用户密码

参考文章 -> http://istester.com/mysql/512.html

6.把/etc/my.cnf中的skip-grant-tables注释掉

参考第2步

ADD free password by idoxu (isTester.com)

skip-grant-tables # IDO老徐注：前面新增一个 “#” 注释掉这行

~

7.重启mysql

参考第3步

搞定，

可以用root新的密码登录了