Can you change primary keys of an collection?

If you can’t change the primaries can I change the selector of a dropdown? For e.g. in my dropdown you can chose between the users emails but not their usernames

using, USER collection, I can Dropdown box of any field, name, IDnumber, full name, emails…
without problem as long as its text or number… it works on my side :man_shrugging:

The question was bad formed. In a form the relationship field is always a dropdown, for users you just can chose between the emails.

You can change which property in a collection is the primary one by re-sorting that to be first top property in the list of properties for that collection on the data tab.