Re: Updating column on row update

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Craig Ringer <craig@postnewspapers.com.au>
Cc: Scott Marlowe <scott.marlowe@gmail.com>, Thom Brown <thombrown@gmail.com>, PGSQL Mailing List <pgsql-general@postgresql.org>, pgsql-hackers@postgresql.org
Date: 2009-11-22T23:51:17Z
Lists: pgsql-hackers, pgsql-general
Craig Ringer <craig@postnewspapers.com.au> writes:
> I do think this comes up often enough that a built-in trigger "update
> named column with result of expression on insert" trigger might be
> desirable.

There's something of the sort in contrib already, I believe, though
it's so old it still uses abstime :-(

> So might "CREATE LANGUAGE ... IF NOT EXISTS". Maybe even "CREATE ROLE
> ... IF NOT EXISTS" and "CREATE USER ... IF NOT EXISTS" - I know I'd find
> them really handy.

CREATE IF NOT EXISTS has been proposed and rejected before, more than
once.  Please see the archives.

			regards, tom lane