```
ModVersion.query.filter_by(ModVersion.mod.game_id == game_id).delete()

AttributeError: Neither 'InstrumentedAttribute' object nor 'Comparator' object associated with ModVersion.mod has an attribute 'game_id'
````
Searching for the exception brought me there: https://stackoverflow.com/a/24763356
Which suggests a bunch of joins, which I can't get to work either.