Re: [SQL] \set

I am not talking about SET, I am talking about \set command.
Yes, I understand, plpgsql can work around it, but I think postgresql
should have a simple way to do it.
E.g.
Db>\set AAA 'whatever'
Db>\set
You will see AAA associate with 'whatever', it's an internal variable,
but how could I use it in my SQL query?

Thanks anyway.

Jie Liang

-----Original Message-----
From: Christian Kratzer [mailto:ck(at)cksoft(dot)de]
Sent: Wednesday, May 12, 2004 3:13 AM
To: Jie Liang
Cc: pgsql-admin(at)postgresql(dot)org; pgsql-sql(at)postgresql(dot)org
Subject: Re: [SQL] \set

Hi,

On Tue, 11 May 2004, Jie Liang wrote:

> Hi,
> How to use an internal variable?
> Original question was how to set a variable in postgresql?
> If I want to set a variable like start_date='2004-05-10';
> How could I use it in my SQL statement?
> E.g.
>
> Db> set start_date '2004-05-10'
> Db> select start_date as 'start date';
>
> It's not executable!

from doc/postgresql/html/sql-set.html

--snipp--
Synopsis

SET [ SESSION | LOCAL ] name { TO | = } { value | 'value' |
DEFAULT }
SET [ SESSION | LOCAL ] TIME ZONE { timezone | LOCAL | DEFAULT }

...
...
...

name

Name of a settable run-time parameter.
Available parameters are documented in Section 16.4 and
below.
--snipp--

that is you can only use SET to change specific predefined parameters.
It does not say you could use SET to store other data local to the
database session.

As far as I know there are no session local variables in postgresql. I
could use something like this myself. The only workaround I know of
to have data local to a session is to create a temporary table for the
data.

There are local variables in plpgsql if you are just looking for local
variables.

Greetings
Christian

--
Christian Kratzer ck(at)cksoft(dot)de
CK Software GmbH http://www.cksoft.de/
Phone: +49 7452 889 135 Fax: +49 7452 889 136