R: Re: Function with DEFAULT arguments

Ok, thanks for the quick reply and the link!

Dario

>----Messaggio originale----
>Da: depesz(at)depesz(dot)com
>Data: 12/03/2010 17.38
>A: "dario(dot)ber(at)libero(dot)it"<dario(dot)ber(at)libero(dot)it>
>Cc: <pgsql-general(at)postgresql(dot)org>
>Ogg: Re: [GENERAL] Function with DEFAULT arguments
>
>On Fri, Mar 12, 2010 at 05:28:57PM +0100, dario(dot)ber(at)libero(dot)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/
>
>depesz
>
>--
>Linkedin: http://www.linkedin.com/in/depesz / blog: http://www.depesz.com/
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>