Few times post come about the question: how to sync or read/migrate metadata from other photo apps to PL. The generic agreement is usually: via xmp sidecar files is the best. Great.
However i wonder some SQL (database) scripts. May like 20+ script, with manual database open, and manually executed the scripts - one after another. What may do the thing, without xmp. So, not app, but readable (and ready to modify) SQL scripts. Can works unlimited amount of cases (items), and execute very-very fast. For ratings (stars), colour flag, keywords at least. May Lr “Collections” → PL “Projects” also can be done.
May even folder and photo also (but i think, PL folder/photo scan/re-index anyhow necessary)
As i already write simple keyword import (from CSV text file) to PL, seems not an impossible thing to do.
I thinkg in the case of Lr and XnView seems it possible. And may not just “one time”, but also incremental way. Under Windows (that’s what i have).
What’s your opinion on that? What Lr version can be interesting? May some of us still use Lr 5.x, 6.x (pre-subscrition) versions (i still has Lr 5.x)