[MySQL] Modify the initial password of the MySQL root account to solve ERROR 1698 (28000): Access denied for user ‘root‘@‘localhost‘

Problem Description

After installing MySQL on Ubuntu, an access denied error occurred when trying to log in using the root account.

mysql -u root -p
Enter password:
ERROR 1698 (28000): Access denied for user 'root'@'localhost'

To solve this problem, we can use the following steps to reset the password of the root account.

First, we need to find the password for the debian-sys-maint user. You can find it with the following command:

sudo cat /etc/mysql/debian.cnf

In the output, find the value of the password field. Make a note of this password, we will use it in the next steps.

You can log in to MySQL using the password of the debian-sys-maint user. Use the following command:

mysql -u debian-sys-maint -p

Enter the password you recorded earlier at the prompt and press Enter.

After successfully logging in to MySQL, you need to switch to the mysql database. Use the following command:

USE mysql;

Change the root user's password. Use the following SQL statement:

UPDATE user SET authentication_string='' WHERE User='root';

ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY 'new_password';

Please replace new_password with the new password you want to set.

After completing the password modification, you need to refresh the permissions for the changes to take effect. Use the following SQL statement:

FLUSH PRIVILEGES;

Use the newly set password to log in to the root account. Use the following command:

mysql -u root -p

Enter the new password you just set at the prompt and press Enter.

If all goes well, you should successfully log in to MySQL.