Drive letter for image filename from database on Windows

Hi,

I'm trying to construct the full image path from the images in the sqlite
database.

I have this file, for example:
X:\Nino\Pictures\2018-03\20160511_162826.jpg

What I have so far is the:
- image filename (images.name): 20160511_162826.jpg
- the relative path in the album (albums.relativePath): /2018-03
- the root path of the album (albumRoots.specificPath): /Nino/Pictures

What I'm missing though is the drive letter.
There is sth. like this in albumRoots.identifier: volumeid:?uuid=c472a11d
But the uuid is completely different(and very short) than what mountvol
gives me:
    \\?\Volume{3293a795-02c3-11e8-b7f0-50e549c6af80}\
        X:\

How is Digikam constructing the filename from the database?

Cheers,
Nino