Backup Join Keys

Is there a way to have a backup join key incase the first one does not match? In my use case, about 80% of the primary join keys match between 2 datasets, but it’s too much dynamic data to do a manual update to make it 100%. I would rather say “if Join key 1 works, use that, if not try key 2.”

I believe a work around could be to join the datasets twice based on both and make columns that pull values from either that are not null.

You can add multiple join keys by clicking the “Add” button under your first join key.

A row has to match all the join keys in order to be considered a match.

That would work if it was an OR function, but for my purposes I would want something like join with CREATED_BY > USEI_ID, if there is not a match on that key, join with EMAIL > USER_EMAIL.