You can tell by trying to edit the values in the result set.
I would try your query first before assuming you can't do it.
You can think of update queries as a powerful form of the Find and Replace dialog box.
Then you use a MUCH simpler query as the forms recordsource, just the temp table joined to the original table via the ID.
This should work, but you now also have some other tasks like emptying the temp table each time before/after you use it and it is not really multi-user friendly.
Unlike the Find and Replace dialog box, an update query lets you: As a best practice when creating an update query, first create a select query that identifies the records that you want to update, and then convert that query to an update query that you can run to update the records.
By selecting data first, you can verify that you’re updating the records you want before you actually change any data.
I have 7 different tables in my database (Artist, Album, Track, Manager, Producer, Recording Studio and Genre) all with Primary Keys and all working great.; microsoft.support = microsoft.support