➥ Grant all privileges to root@localhost for mariadb or mysql on ubuntu 16.04 to use phpmyadmin

If you have ever had a problem to login to phpmyadmin with root you will need to add the rights.
login to mariadb/mysql:
mysql -uroot -p

check if user is added:
SELECT User, Host FROM mysql.user WHERE Host <> 'localhost';

[quote]
MariaDB [(none)]> SELECT User, Host FROM mysql.user WHERE Host <> 'localhost';
+----------+------+
| User | Host |
+----------+------+
| librenms | % |
+----------+------+

Now add the root user:
GRANT ALL PRIVILEGES ON *.* TO 'root'@'localhost' IDENTIFIED BY 'YOUR PASSWORD' WITH GRANT OPTION;

And now flush:
flush privileges;

[quote]
MariaDB [(none)]> SELECT User, Host FROM mysql.user WHERE Host <> 'localhost';
+----------+-------------+
| User | Host |
+----------+-------------+
| librenms | % |
| root | % |
+----------+-------------+