Uninstalled and re-installed MariaDB. Digikam can't connect to re-installation

This is a crosspost, as I struggle to find out, which one the best community is to find help with MariaDB/KDE-digikam.

I had a working installation of digikam [latest, version probably irrelevant] and MariaDB 10.6 on my system. I had tagged a bunch of photos, especially faces with the face tags. The tags are written to the individual file metadata, but the face tags, of course, are not, as far as I know.

I accidentally uninstalled MariaDB (I know. How do you “accidentally” uninstall software?!), then, next PC session, I opened digikam and it told me it can’t connect to the database. That’s when I realized my mistake. The program files were still there under “C:\Program Files\MariaDB 10.6\data”, so I promptly proceded to make a backup copy of the folder to another drive.

I re-installed MariaDB (v11.something), then copied the digikam folder from the backup to the new data folder. I connect to the service with HeidiSQL and click on a table in the digikam database and get the following error message (translated from German, so it might not be exactly that in English):

This view might contain an error in the code.

SQL Error (1932): Table ‘digikam.albumroots’ doesn’t exist in the engine.

I also tried with the correct version 10.6 of MariaDB, but get exactly the same result. Replacing the entire ‘data’ folder by the old one doesn’t help, either. I think I can’t even connect to the database when doing so. I can do it again if this is important. I also ran the following in the console (with result):

>mysqlcheck -u root -p --repair digikam
Enter password: ***
Error : Table ‘digikam.albumroots’ doesn’t exist in engine
status : Operation failed
Error : Table ‘digikam.albums’ doesn’t exist in engine
status : Operation failed

Basically, my question is this: How do I re-install MariaDB correctly so I can re-access the digikam database? Unfortunately, I don’t even know where to start. If you have at least an idea or a hint about what could be wrong, that will certainly help me further along my quest.

In the worst of cases, I’ll start over, but I’d really rather not.