> 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?
That is correct, and it is on the ToDo list as something like "allow
subselects in target expressions" (though I'm not finding it when I
look).
However, as you suspect you can rephrase it:
tgl=> update x set c = j.c from x as j where j.i = 1 and x.i = 0;
UPDATE 1
tgl=> select * from x;
i|c
-+-
1|T
2|A
0|T
(3 rows)
- Tom
