Immich 1.122, a self-hosted photo and video backup solution, introduces HDR video support, auto server URL switching, custom email templates, and more.
As in "While the photos are still in your storage, the DB is gone for good and a manual reimport from the existing files is not possible, so you have three options:
Restoring the DB from a working backup
Reinstalling and reuploading the data
Reinstalling and importing the existing data as external libraries - which will lead to duplicates in your users galleries as soon as their devices sync themselves with Immich"
Honestly, you really don't want options 2 and 3. Just make sure you've got good backups of everything. My DB is backed up daily and I keep periodic backups for up to three years just to be sure.