update and select

Let's say I have a table test like this:

i|c
-+-
2|A
0|
1|T
(3 rows)

and I want to use an update to do the following: set the attr c of the
record with number 0 to the value of attr c in the record with number 1.

In Oracle I'd be able to write:

update test set c = (select c from test where i = 1) where i = 0;

Is it correct that we do not allow this? Pardon me if this is already on
todo, but I just stumbled across this problem and I'm not sure I can work
around this by using the from clause (which btw Oracle doesn't even have).
Since we do have subselects this shouldn't be too difficult.

Michael
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