mysql 

MariaDB [(none)]> create database nextcloud; 
Query OK, 1 row affected (0.001 sec)

MariaDB [(none)]> create user 'nc_user'@'localhost' identified by 'nc_pass';
Query OK, 0 rows affected (0.001 sec)

MariaDB [(none)]> grant all privileges on nextcloud.* to 'nc_user'@'localhost' identified by 'nc_pass';
Query OK, 0 rows affected (0.001 sec)

MariaDB [(none)]> flush privileges;
Query OK, 0 rows affected (0.001 sec)

MariaDB [(none)]> exit;
Bye