I was facing the same problem when using mariaDB with phpmyadmin (Ubuntu 16.04LTS).
Firstly, try to follow below post for install MariaDB or MySQL:
Prerequisites:
1) Install MariaDB
sudo apt-get -y install mariadb-server mariadb-client
sudo mysql_secure_installation (answer to some interactive questions):
Enter current password for root (enter for none): <enter>
Set root password: n
Remove anonymous users: n
Disallow root login remotely: n
Remove test database and access to it: n
Reload privilege tables now: Y
If you want to uninstall mariaDB:
sudo apt-get purge mysql-server mysql-client mysql-common mysql-server-core-5.5 mysql-client-core-5.5
sudo rm -rf /etc/mysql /var/lib/mysql
sudo apt-get autoremove
sudo apt-get autoclean
2) Install phpmyadmin
sudo apt-get -y install phpmyadmin (and answer some interactive questions)
Configuring phpmyadmin:
Web server to reconfigure automatically: apache2
Configure database for phpmyadmin with dbconfig-common: Yes
MySQL application password for phpmyadmin: <blank>
3) In apache2, create a symbolic link to phpmyadmin
sudo ln -s /etc/phpmyadmin/apache.conf /etc/apache2/conf-available/phpmyadmin.conf
sudo a2enconf phpmyadmin.conf
sudo service apache2 restart
Ok, now, if you follow Rael’s instructions, you’ll be able to login into phpmyadmin, but, at least for me, I wasn’t able to create new databases, as a red message came up: No privileges (or some similar message)
The fix was by reconfiguring phpmyadmin, and by answering some interactive questions.
sudo dpkg-reconfigure phpmyadmin
<Ok>
Reinstall database for phpmyadmin: <Yes>
Connection method for MySQL database server for phpmyadmin: TCP/IP
Host name of the MySQL database server for phpmyadmin: localhost
Port number for the MySQL service: 3306
MySQL database name for phpmyadmin: phpmyadmin
<Ok>
MySQL username for phpmyadmin: root
MySQL application password for phpmyadmin: pass # OR ANY PASSWORD YOU WANT
Password confirmation: pass
Name of the database’s administrative user: root
Web server to reconfigure automatically: apache2
An error occurred while installing the database: ignore
Now if you try connect into phpmyadmin (localhost/phpmyadmin) using
username: root
password: pass
you’ll be able to create databases.
Secondly, if you get the error as this post’s title, then try:
~# sudo mysql -u root
MariaDB [(none)]> use mysql;
MariaDB [(none)]> update user set plugin=” where User=’root’;
MariaDB [(none)]> flush privileges;
MariaDB [(none)]> exit;
