Toot@rapidspace:~# mysql -u root -p

Enter password:

Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MariaDB connection id is 50

Server version: 10.3.27-MariaDB-0+deb10ul Debian 10

Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

MariaDB [(none)]> CREATE DATABASE nextclouddb;
Query OK, 1 row affected (0.000 sec)

MariaDB [(none)]> GRANT ALL ON nextclouddb.* TO 'nextcloud_user'@'localhost' IDENTIFIED BY 'strong password';
Query OK, @ rows affected (0.000 sec)

MariaDB [(none)]> FLUSH PRIVILEGES;
Query OK, @ rows affected (0.000 sec)

MariaDB [(none)]> EXIT;
Bye

Font@ranidenare - ~#