SQL Server doesn't support the standard SQL syntax for this but it does
have a proprietary syntax to do the same job:

UPDATE T1
SET x = foo,
y = bar
FROM
(SELECT foo, bar /* your query here */
FROM ... ) AS T2
WHERE T2.key_col = T1.key_col
/* join condition should yield a single row from T2 for each row in
T1 */

> I've always used cursors for
> scrolling through resultsets

Really? For what purpose? Cursors should be the rare exception rather
than the rule. Usually there are better set-based solutions.

--
David Portas
SQL Server MVP
--