Debian 10 Buster - difficulty setting up mariaDB 10.3.27 users for use with Debian mediawiki 1.31 package

[Keith Christian <keith1christian@gmail.com>]

I start out with:
     sudo apt -y install mediawiki
and it installs all packages including mariadb without problems.

Then, when starting to configure mediawiki with the web page, a
database has to be created along with a db user for mediawiki's use:
     http://localhost/mediawiki/mw-config/index.php?page=Welcome

I left Database host as "localhost"
I set Database name as "mediawiki"
Database table prefix is left blank
User account for installation is '"root"
.....and so on.

I started Mariadb immediately after installation with:
    sudo mysqld_safe --skip-grant-tables --skip-networking &

Next, I logged in with this:
     mysql -u root -p

But as I remembered, (it's been awhile) one cannot create any users in
this mode due to --skip-grant-tables.

E.g. I can create these users when logging in with mysql -u root:
     create user 'root'@'localhost' identified by 'foo123';
     create user 'mediawiki'@'localhost' identified by 'baz123';

but I can't log in with either user after restarting MariaDB with:
     sudo systemctl start mariadb

Seems I must always log in with
    mysql -u root -p

There are lots of web pages mentioning this problem but none are
complete enough and my attempts have failed.

SO.....Looking for a "bulletproof" document to set up MariaDB users so
I can get on with configuring Mediawiki.

I don't want to login as a 'root'@'localhost' user for routine DB work
and would rather use the 'mediawiki'@localhost' user for that.

Thanks.