Update Syntax

On Fri, Jan 30, 2004 at 07:41:18 -0800,
"Edwin S. Ramirez" <ramirez@idconcepts.org> wrote:

Hello,

I need Postgres support for the following update syntax :

update table1 set (col1, col2, col3) = (select f1, f2, f3 from table2
where id=5) where rownum=3;

update table1 set (col1, col2, col3) = (select f1, f2, f3 from table2
where id=table1.parentid) where rownum=3;

These type of update statements are the only ones supported by Oracle
to update one table from another.

As a work around you could do:
update table1 set
col1 = (select f1 from table2 where id=table1.parentid),
col2 = (select f2 from table2 where id=table1.parentid),
col3 = (select f3 from table2 where id=table1.parentid)
where rownum=3;

I don't think this will run as efficiently and it makes the query look
more complex, but it should work for both Oracle and Postgres.