It confuses both Psalm and PHPStan, and involves complicated mocking.

This hack is temporary and should be removed on 3.0.x

See https://github.com/vimeo/psalm/issues/3224

This is precisely what we are testing here.

This is what is expected with FETCH_COLUMN

Not all RDBMS have a concept of database, apparently (see SQLAnywhere).
Those who do not should pass in a string to stay compatible with the
signature.

The method signature does not allow null.

We are testing what happens when providing the wrong type.

It is more simple and more accurate