found a way to update a table with data from another one

Hi everybody
I've read a quite old posting about the impossibility of updating a
view.
e.g.

Let t1 (Id, balance) and t2 (id, amount) be two tables

DEFINE VIEW U AS SELECT balance, amount FROM t1, t2 WHERE t1.id=t2.id;
UPDATE U SET balance=balance+amount

without writing a rule

I found a simpler way to do the job I wanted done

UPDATE t1 SET  balance = balance+t2.amount WHERE EXISTS (SELECT *
FROM t2 WHERE t2.id = t1.id)

DOES WORK PROPERLY.