Re: Notiffy problem

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

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Merlin Moncure <mmoncure@gmail.com>
Cc: adasko98 <adasko.86@gmail.com>, pgsql-general@postgresql.org
Date: 2012-06-29T15:10:15Z
Lists: pgsql-general
Merlin Moncure <mmoncure@gmail.com> writes:
> On Fri, Jun 29, 2012 at 8:58 AM, adasko98 <adasko.86@gmail.com> wrote:
>>>>     Notify demoApp, n_user ;<----here is a problem

>>> Looks like a limitation of the plpgsql parser, perhaps even counts as a
>>> bug.

It is not a bug, but a documented limitation of the NOTIFY command: the
payload has to be a simple string literal.

(The technical reason for that is that NOTIFY isn't a plannable
statement, but a utility command, and utility commands generally don't
evaluate expressions.  In principle we could fix that, but in practice
it's not going to change, because the pg_notify() function serves just
fine for every case where you want a non-constant payload.)

			regards, tom lane