我遇到ubuntu 18.04和mysql 5.7的问题，这是解决方案

执行命令前请尝试重新启动mysql-server

sudo service mysql restart

Mysql-server >= 5.7

sudo mysql -uroot -p
USE mysql;
UPDATE user SET authentication_string=PASSWORD('YOUR_PASSWORD') WHERE User='root';
UPDATE user SET plugin="mysql_native_password";
FLUSH PRIVILEGES;
quit;

Mysql-server < 5.7

sudo mysql -uroot -p
USE mysql;
UPDATE user SET password=PASSWORD('YOUR_PASSWORD') WHERE User='root';
UPDATE user SET plugin="mysql_native_password";
FLUSH PRIVILEGES;
quit;

官方和简单的方法来重置根密码在ubuntu服务器…

如果你在16.04 14.04 12.04

sudo dpkg-reconfigure mysql-server-5.5

如果你在10.04:

sudo dpkg-reconfigure mysql-server-5.1

如果您不确定安装了哪个mysql-server版本，您可以尝试:

dpkg --get-selections | grep mysql-server

mysql-server-5.7的更新说明

请注意，如果您使用的是mysql-server-5.7，则不能使用上面所示的更简单的dpkg-reconfigure方法。

如果你知道密码，登录并运行这个:

UPDATE mysql.user SET authentication_string=PASSWORD('my-new-password') WHERE USER='root';
FLUSH PRIVILEGES;

或者，您可以使用以下方法:

sudo mysql_secure_installation

这将询问您一系列关于保护安装的问题(强烈推荐)，包括是否需要提供新的根密码。

如果你不知道root密码，请参考这个以ubuntu为中心的进程写上去。

查看更多信息:

https://help.ubuntu.com/16.04/serverguide/mysql.html https://help.ubuntu.com/14.04/serverguide/mysql.html

正如mysql文档中password()函数所说:

此函数在MySQL 8.0.11中被移除。

这将使mysql v8.0.11及更新版本的所有现有答案都失效。

根据mysql文档，重置root密码的新通用方法如下:

The preceding sections provide password-resetting instructions specifically for Windows and Unix and Unix-like systems. Alternatively, on any platform, you can reset the password using the mysql client (but this approach is less secure): Stop the MySQL server if necessary, then restart it with the --skip-grant-tables option. This enables anyone to connect without a password and with all privileges, and disables account-management statements such as ALTER USER and SET PASSWORD. Because this is insecure, if the server is started with the --skip-grant-tables option, it enables --skip-networking automatically to prevent remote connections. Connect to the MySQL server using the mysql client; no password is necessary because the server was started with --skip-grant-tables: shell> mysql In the mysql client, tell the server to reload the grant tables so that account-management statements work: mysql> FLUSH PRIVILEGES; Then change the 'root'@'localhost' account password. Replace the password with the password that you want to use. To change the password for a root account with a different host name part, modify the instructions to use that host name. mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'MyNewPass'; You should now be able to connect to the MySQL server as root using the new password. Stop the server and restart it normally (without the --skip-grant-tables and --skip-networking options).

Instead of resetting the password there is a work around on the local machine if you have setup phpmyadmin to connect without giving the password or username. Check this out by starting mysql, apache etc. I have xampp installed in my local machine. So starting the xampp will start all the necessary services. Now going to http://localhost/phpmyadmin shows me all the databases. This confirms that you have saved the username and passsword in the config file of phpmyadmin which can be found in the phpmyadmin install location. If you have xampp installed the phpmyadmin folder can be found in the root folder of xampp installation. Search for the word password in the config.inc.php file. There you will find the password and username.

当你在你想要更改密码的系统上使用MySQL的PASSWORD()时，它可能会导致密码在MySQL日志中以cleartext [source]显示。对我来说，让它们和备份等像密码一样安全听起来像是噩梦，所以我喜欢这样做:

On your local machine, run this with your password: mysql -u someuser -p < <(echo "SELECT PASSWORD('mypass');") Note the space in front to prevent it from turning up in the bash history (for other distros than Ubuntu, this might work differently – source). On your server machine, execute the following command to change its MySQL root password (replace myhash with your password's hash as printed by the first command): mysql -u root -p < <(echo "SET PASSWORD FOR root@localhost = 'myhash';") Optionally, let's be a bit paranoid: On your local machine, clear your terminal screen with clear and purge your virtual terminal scrollback, to hide the cleartext password appearing in the command above.

要更新“root”Mysql用户密码，你必须记住，你将需要超级用户权限。如果您拥有超级用户权限，请尝试执行以下命令:

MySQL 5.7.6及以上版本

sudo su
service mysql stop
mysql -u root
ALTER USER 'root'@'localhost' IDENTIFIED BY 'MyNewPass';
\q;
exit
mysql -u root -p MyNewPass

MySQL 5.7.5及更早版本

sudo su
service mysql stop
mysql -u root
SET PASSWORD FOR 'root'@'localhost' = PASSWORD('MyNewPass');
\q;
exit
mysql -u root -p MyNewPass