R: Re: Function with DEFAULT arguments

Ok, thanks for the quick reply and the link!

Dario

----Messaggio originale----
Da: depesz@depesz.com
Data: 12/03/2010 17.38
A: "dario.ber@libero.it"<dario.ber@libero.it>
Cc: <pgsql-general@postgresql.org>
Ogg: Re: [GENERAL] Function with DEFAULT arguments

On Fri, Mar 12, 2010 at 05:28:57PM +0100, dario.ber@libero.it wrote:

Hello,

I'm trying to use the DEFAULT option to pass parameters to the arguments of

a

function.
When I call that function, how can I change the default value of some
arguments and leave as default the value of other arguments? In other

words, is

there a way to 'call' the arguments by their names so to specify which

should

have their default value changed?

Here's a toy example, a function that takes three strings as arguments and
concatenate them:

CREATE FUNCTION test_default(string1 text default 'a', string2 text

default

'b', string3 text default 'c') RETURNS text AS $$
BEGIN
RETURN string1 || string2 || string3;
END;
$$ language 'plpgsql';

-- Only default args:
SELECT test_default(); --> abc

-- With custom values:
SELECT test_default('X', 'Y', 'Z'); --> XYZ

-- Now, how can I leave as default the 1st and 3rd argument (string1 and
string3) and change only the second one (string2)? I would like to do

something

like:

You can't unless you're on PostgreSQL 9.0:
http://www.depesz.com/index.php/2009/11/17/waiting-for-8-5-named-function-

arguments/