我还没有看到MySQL 8.0指南中推荐的官方步骤，这是唯一适合我的步骤。下面是这些步骤的总结。

Stop the MySQL server if it is running. Look in /var/lib/mysql/, /var/run/mysqld/, or /usr/local/mysql/data/ to find the pid file with the server's process ID. Generally the file begins with either mysqld or your system's host name and ends with .pid. Replace mysql-data-directory and host_name that you just found, in the following command: $ sudo kill `sudo cat /mysql-data-directory/host_name.pid` This command will create a text file in /tmp/mysql-init with the SQL statement and makes the mysql user the owner. Replace in the command MyNewPass with your own password. $ echo "ALTER USER 'root'@'localhost' IDENTIFIED BY 'MyNewPass';" > /tmp/mysql-init && sudo chown mysql /tmp/mysql-init Start the MySQL server by running the following command on the command line. After this the password is updated and you can close the server again with CTRL+C. $ sudo mysqld --user=mysql --init-file=/tmp/mysql-init & Remove the temporary file with your password: $ sudo rm /tmp/mysql-init

唯一对我有效的方法是这里描述的(我运行的是ubuntu 14.04)。为了清晰起见，以下是我遵循的步骤:

sudo vim /etc/mysql/my.cnf Add the following lines at the end: [mysqld] skip-grant-tables sudo service mysql restart mysql -u root use mysql select * from mysql.user where user = 'root'; - Look at the top to determine whether the password column is called password or authentication_string UPDATE mysql.user set *password_field from above* = PASSWORD('your_new_password') where user = 'root' and host = 'localhost'; - Use the proper password column from above FLUSH PRIVILEGES; exit sudo vim /etc/mysql/my.cnf Remove the lines added in step 2 if you want to keep your security standards. sudo service mysql restart

参考:https://dev.mysql.com/doc/refman/5.7/en/resetting-permissions.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).

停止MySQL Sudo service mysql stop 制作MySQL服务目录。 Sudo mkdir /var/run/mysqld 赋予MySQL用户写入服务目录的权限。 Sudo chown mysql: /var/run/mysqld 手动启动MySQL，不需要权限检查或联网。 Sudo mysqld_safe—skip-grant-tables—skip-networking &

5.无需密码登录。 Mysql -uroot Mysql

6.更新root用户密码。

更新mysql。user SET authentication_string=PASSWORD('YOURNEWPASSWORD')， plugin='mysql_native_password' WHERE user ='root' AND Host='%'; 退出;

关闭MySQL。 sudo mysqladmin -S /var/run/mysqld/mysqld.袜子关闭 正常启动MySQL服务。 Sudo服务mysql启动

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;

这就是我的解决方案。我在Ubuntu 18.04工作: https://stackoverflow.com/a/46076838/2400373

但是重要的是最后一步的改变:

UPDATE mysql.user SET authentication_string=PASSWORD('YOURNEWPASSWORD'), plugin='mysql_native_password' WHERE User='root' AND Host='localhost';