[SOLVED] ERROR 1698 (28000): Access denied for user 'root'@'localhost'

The reason is that recent Ubuntu installation (maybe others also), mysql is using by default the UNIX auth_socket plugin.

Basically means that: db_users using it, will be "auth" by the system user credentias. You can see if your root user is set up like this by doing the following:

$ sudo mysql -u root # I had to use "sudo" since is new installation

mysql> USE mysql;

mysql> SELECT User, Host, plugin FROM mysql.user;

+------------------+-----------------------+
| User             | plugin                |
+------------------+-----------------------+
| root             | auth_socket           |
| mysql.sys        | mysql_native_password |
| debian-sys-maint | mysql_native_password |
+------------------+-----------------------+

As you can see in the query, the root user is using the auth_socket plugin

There are 2 ways to solve this:

1. You can set the root user to use the mysql_native_password plugin
2. You can create a new db_user with you system_user (recommended)

Option 1:

$ sudo mysql -u root # I had to use "sudo" since is new installation

mysql> USE mysql;

mysql> UPDATE user SET plugin='mysql_native_password' WHERE User='root';

mysql> FLUSH PRIVILEGES;

mysql> exit;

$ service mysql restart

Option 2:

(replace YOUR_SYSTEM_USER with the username you have)

$ sudo mysql -u root # I had to use "sudo" since is new installation

mysql> USE mysql;

mysql> CREATE USER 'YOUR_SYSTEM_USER'@'localhost' IDENTIFIED BY '';

mysql> GRANT ALL PRIVILEGES ON *.* TO 'YOUR_SYSTEM_USER'@'localhost';

mysql> UPDATE user SET plugin='auth_socket' WHERE User='YOUR_SYSTEM_USER';

mysql> FLUSH PRIVILEGES;

mysql> exit;

$ service mysql restart

Remember that if you use option #2 you'll have to connect to mysql as your system username (mysql -u YOUR_SYSTEM_USER)

Note: On some systems (e.g., Debian stretch) 'auth_socket' plugin is called 'unix_socket', so the corresponding SQL command should be: UPDATE user SET plugin='unix_socket' WHERE User='YOUR_SYSTEM_USER';

Sumber: stackoverflow.com