Join with keys with prefix

Hi all,

I have these documents on a same bucket, I would like to join them using N1ql.
The prefix for the keys change according to the application name.

document Key is “InventoryApplication4567”

   email: "",
   countryId: "1234",
   type: "customer"

document Key is “InventoryApplication1234”

   name: "United States",
   type: "country"

Can somebody please help me make a JOIN query using n1ql for this case?

FROM default AS t
JOIN default AS c
ON KEYS "InventoryApplication"||t.countryId
WHERE .....;

In 5.5 you can use ANSI JOINS