The @@identity
and scope_identity()
will hand you the identity of a new row, ie. after an insert. After your update, the identity of the row is… @Customer_ID or @Handle_Id? If it is a different field, you should use the OUTPUT clause to return the ID of the updated row:
UPDATE ITS2_UserNames
SET AupIp = @AupIp
OUTPUT INSERTED.PrimaryKeyID
WHERE @Customer_ID = TCID AND @Handle_ID = ID