Use case:
Importing data from different clients, each uses a different currency. Each client is a difference CSV. Ideally I can set the currency for that import when I’m importing that CSV.
The other options are either importing then setting. Or fixing it in the csv before importing.
What does this mean? A currency field is just a number field with some extra formatting, and the formatting is the same for every entity in the db.
If you’re importing USD amounts one minute and the importing EUR amounts the next, surely you need to import into different fields each time.
So your example is a specific case of a more general need of wanting to import a CSV file whilst setting a fixed value for a to-one relation field (which is otherwise not present in the csv data) right?
Exactly. Sometimes when exporting data from a provider, you can only do it one X at a time (per client, per currency, per whatever). Then this value is not visible in the CSV as it is the same for all of then, this is the use case a feature like this would be helpful.
Another use case is tracking imports. Not super needed because the Creation Date tells you when things were created, but might be useful in some cases. So you have an “Import” database, and link to a new entity every time you import, for example.