easy way to update table_a set value=table_b.value where... ?

I'm wondering whether there is a simple way to accomplish the following:

table a(id, a1,a2...)
table b(id, b1,b2..)

--update all ideal columns in table, like:--
update table_a set a.a1=table_b.b1 where a.id=b.id and a2<>b2

--

Thanks lots
John Wu
Toronto Received on Mon Mar 10 2003 - 14:10:14 CET