在Linux下安装了MySQL5.7.24，重新设置密码的时候竟然忘记root密码了，没办法，只能重新搞一下，亲测可用。

此处我用的是MySQL5.7.24的方法，其他版本的MySQL用这个方法或许不一样。

首先结束当前正在运行的mysql进程

linuxidc@linuxidc:~$ sudo /etc/init.d/mysql stop

[ ok ] Stopping mysql (via systemctl): mysql.service.

用mysql安全模式运行并跳过权限验证

linuxidc@linuxidc:~$ sudo mysqld_safe --user=mysql --skip-grant-tables --skip-networking &

[1] 22024

linuxidc@linuxidc:~$ 2018-11-01T08:39:38.987953Z mysqld_safe Logging to syslog.

2018-11-01T08:39:38.992011Z mysqld_safe Logging to '/var/log/mysql/error.log'.

2018-11-01T08:39:39.012604Z mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql

用空密码方式使用root用户登录 MySQL

linuxidc@linuxidc:~$ sudo  mysql -u root mysql

Reading table information for completion of table and column names

You can turn off this feature to get a quicker startup with -A

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

Your MySQL connection id is 2

Server version: 5.7.24-0Ubuntu0.18.04.1 (Ubuntu)

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.

更新密码

mysql> update user set Password = PASSWORD('root') where User ='root';

ERROR 1054 (42S22): Unknown column 'Password' in 'field list'

执行后报错 　ERROR 1054(42S22) Unknown column 'password' in ‘field list’

错误的原因是MySQL 5.7版本下的mysql数据库下已经没有password这个字段了，password字段改成了authentication_string

所以请使用一下命令：

mysql> use mysql;

Database changed

mysql> select User from user;    #此处为查询用户命令

+------------------+

| User            |

+------------------+

| debian-sys-maint |

| mysql.session    |

| mysql.sys        |

| root            |

+------------------+

4 rows in set (0.00 sec)

mysql> update mysql.user set authentication_string=password('root') where user='root';  #修改密码成功

Query OK, 1 row affected, 1 warning (0.11 sec)

Rows matched: 1  Changed: 1  Warnings: 1

mysql> flush privileges;    #刷新权限立即生效

Query OK, 0 rows affected (0.05 sec)

退出

mysql> quit

Bye