之前的答案都没有帮助我解决这个问题，所以这里是我找到的解决方案。

相关部分:

In Ubuntu systems running MySQL 5.7 (and later versions), the root MySQL user is set to authenticate using the auth_socket plugin by default rather than with a password. This allows for some greater security and usability in many cases, but it can also complicate things when you need to allow an external program (e.g., phpMyAdmin) to access the user. In order to use a password to connect to MySQL as root, you will need to switch its authentication method from auth_socket to mysql_native_password. To do this, open up the MySQL prompt from your terminal: sudo mysql Next, check which authentication method each of your MySQL user accounts use with the following command: SELECT user,authentication_string,plugin,host FROM mysql.user; Output +------------------+-------------------------------------------+-----------------------+-----------+ | user | authentication_string | plugin | host | +------------------+-------------------------------------------+-----------------------+-----------+ | root | | auth_socket | localhost | | mysql.session | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE | mysql_native_password | localhost | | mysql.sys | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE | mysql_native_password | localhost | | debian-sys-maint | *CC744277A401A7D25BE1CA89AFF17BF607F876FF | mysql_native_password | localhost | +------------------+-------------------------------------------+-----------------------+-----------+ 4 rows in set (0.00 sec) In this example, you can see that the root user does in fact authenticate using the auth_socket plugin. To configure the root account to authenticate with a password, run the following ALTER USER command. Be sure to change password to a strong password of your choosing, and note that this command will change the root password you set in Step 2: ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY 'password'; Then, run FLUSH PRIVILEGES which tells the server to reload the grant tables and put your new changes into effect: FLUSH PRIVILEGES; Check the authentication methods employed by each of your users again to confirm that root no longer authenticates using the auth_socket plugin: SELECT user,authentication_string,plugin,host FROM mysql.user; Output +------------------+-------------------------------------------+-----------------------+-----------+ | user | authentication_string | plugin | host | +------------------+-------------------------------------------+-----------------------+-----------+ | root | *3636DACC8616D997782ADD0839F92C1571D6D78F | mysql_native_password | localhost | | mysql.session | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE | mysql_native_password | localhost | | mysql.sys | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE | mysql_native_password | localhost | | debian-sys-maint | *CC744277A401A7D25BE1CA89AFF17BF607F876FF | mysql_native_password | localhost | +------------------+-------------------------------------------+-----------------------+-----------+ 4 rows in set (0.00 sec) You can see in this example output that the root MySQL user now authenticates using a password. Once you confirm this on your own server, you can exit the MySQL shell: exit

根据MariaDB官方文档，在MariaDB 10.4.3及以后版本中，默认安装了unix_socket身份验证插件。

为了禁用它，并恢复到前面的mysql_native_password认证方法，在my.cnf文件的[mysqld]部分中添加下面的行:

[mysqld]
unix_socket=OFF

然后运行:

mysql_install_db --auth-root-authentication-method=normal

然后启动mysqld

这个命令可以正常工作:

mysqladmin -u root password CHANGEME

有关更多信息，请参见配置mysql_install_db恢复到以前的身份验证方法。

有时会在安装时设置默认密码-如文档中所述。可以通过以下命令确认。

sudo grep 'temporary password' /var/log/mysqld.log

我在这里的位置:

UBUNTU 21.04 PHP 5.6.40-57 MYSQL 5.7.37

我们来配置一下

nano /etc/mysql/mysql.conf.d/mysqld.cnf

在底部，写下这个

skip-grant-tables

重新加载它

service mysql restart

'-p'参数不要求参数名和值之间有空格。

而不是

./mysqladmin -u root -p 'redacted'

Use

./mysqladmin -u root -p'redacted'

或者只是

./mysqladmin -u root -p

这将提示您输入密码。

对于Ubuntu/Debian用户

(它可能适用于其他发行版，尤其是基于debian的发行版。)

运行以下命令以root身份连接(不需要任何密码)

sudo /usr/bin/mysql --defaults-file=/etc/mysql/debian.cnf

如果你不想每次以根用户连接时都添加——defaults-file，你可以将/etc/mysql/debian.cnf复制到你的主目录:

sudo cp /etc/mysql/debian.cnf ~/.my.cnf

然后:

sudo mysql