MySQL用户密码管理问题总结

MySQL用户密码管理问题总结

一、忘记root用户密码

如果忘记了root密码，可以采用以下方法：

1、停止mysql服务

[root@bogon /]# systemctl stop mysqld

2、修改配置文件（my.cnf）

在【mysqld】选项中加入skip grant tables

[mysqld]
skip-grant-tables
.....

3、启动mysql服务

[root@bogon /]# systemctl start mysqld
[root@bogon /]# mysql -uroot 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.7.27-log MySQL Community Server (GPL)

Copyright (c) 2000, 2019, 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.

此时，可以不输入密码登录。

4、更改密码

此时无法使用set password命令，可以使用update更新user表。命令如下：

mysql> select host,user from mysql.user;
+-------------+---------------+
| host        | user          |
+-------------+---------------+
| 192.168.1.% | repl          |
| localhost   | admin         |
| localhost   | mysql.session |
| localhost   | mysql.sys     |
| localhost   | root          |
| localhost   | wang          |
+-------------+---------------+
6 rows in set (0.00 sec)

mysql> update mysql.user set authentication_string=password('Wgx123456.') where user='root' and host='localhost';
Query OK, 0 rows affected, 1 warning (0.00 sec)
Rows matched: 1  Changed: 0  Warnings: 1

mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

5、修改配置文件

重新修改配置文件，把【mysqld】选项中的skip grant tables命令删除或者注释掉。

[mysqld]
# skip-grant-tables
.....

6、重新启动mysql服务

[root@bogon /]# systemctl restart mysqld
[root@bogon /]# mysql -uroot -pWgx123456.
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 2
Server version: 5.7.27-log MySQL Community Server (GPL)

Copyright (c) 2000, 2019, 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.

此时，已经可以使用新密码登录MySQL了。

二、修改root用户密码（知道root账户的原有密码）

1、使用mysqladmin命令修改用户密码

该命令不需要登录MySQL，格式如下：

shell> mysqladmin -uroot -p password "newpwd";

例如：修改root用户的密码，执行该命令后输入原来的root账户密码，则root密码被设置为新密码。

[root@bogon ~]# mysqladmin -uroot -p password 'Zhao@123456'
Enter password: 
mysqladmin: [Warning] Using a password on the command line interface can be insecure.
Warning: Since password will be sent to server in plain text, use ssl connection to ensure password safety.
[root@bogon ~]# mysql -uroot -pZhao@123456
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 12
Server version: 5.7.27-log MySQL Community Server (GPL)

Copyright (c) 2000, 2019, 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.

2、登录MySQL，修改root账户密码

（1）使用set passwor命令

mysql> set password=password('Wgx123456.');
Query OK, 0 rows affected, 1 warning (0.01 sec)

（2）修改user表

mysql> update mysql.user set authentication_string=password('Wgx123456.') 
       where user='root' and host='localhost';
Query OK, 0 rows affected, 1 warning (0.00 sec)
Rows matched: 1  Changed: 0  Warnings: 1

三、修改其他用户的密码

1、使用root账户登录

先使用root账户登录，使用以下命令可以修改任何用户的密码。

set password for '用户名'@'主机名' = password ('新密码');

例如，修改用户wang的登录密码。

mysql> select host,user from mysql.user;
+-------------+---------------+
| host        | user          |
+-------------+---------------+
| 192.168.1.% | repl          |
| localhost   | admin         |
| localhost   | mysql.session |
| localhost   | mysql.sys     |
| localhost   | root          |
| localhost   | wang          |
+-------------+---------------+
6 rows in set (0.00 sec)

mysql> set password for 'wang'@'localhost' = password('Wang@123456');
Query OK, 0 rows affected, 1 warning (0.01 sec)

2、用要修改密码的账户登录

[root@bogon /]# mysql -uwang -pWang@123456
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 3
Server version: 5.7.27-log MySQL Community Server (GPL)

Copyright (c) 2000, 2019, 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> set password=password('Wang123456.');
Query OK, 0 rows affected, 1 warning (0.01 sec)