Re: aggregation of setof

From: Andreas Gaab <A(dot)Gaab(at)scanlab(dot)de>
To: "pgsql-sql(at)postgresql(dot)org" <pgsql-sql(at)postgresql(dot)org>
Subject: Re: aggregation of setof
Date: 2011-01-31 10:22:23
Message-ID: 48DA836F3865C54B8FBF424A3B775AF6671A6838F9@Exchange-Server
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-sql

Hi,

Could not the function regexp_matches(text, text) be defined to only return a text[] not a setof text[]?

Because that is, what it actually does, or? For every input, it returns only one output row. The function regexp_matches(text,text,text) in contrast really can return multiple rows while only receiving one row.

Regards,
Andreas

-----Ursprüngliche Nachricht-----
Von: Pavel Stehule [mailto:pavel(dot)stehule(at)gmail(dot)com]
Gesendet: Montag, 31. Januar 2011 10:24
An: Andreas Gaab
Cc: pgsql-sql(at)postgresql(dot)org
Betreff: Re: [SQL] aggregation of setof

Hello

use a array constructor instead

SELECT ARRAY(SELECT ...)

Regards

Pavel Stehule

2011/1/31 Andreas Gaab <A(dot)Gaab(at)scanlab(dot)de>:
> Functions apparently cannot take setof arguments.
>
>
>
> Postgres 8.4:
>
>
>
> CREATE OR REPLACE FUNCTION testtable(IN setof anyarray)
>
>   RETURNS anyarray AS
>
> $BODY$
>
> SELECT $1 LIMIT 1;
>
> $BODY$
>
>   LANGUAGE 'sql' STABLE;
>
>
>
> à
>
> ERROR:  functions cannot accept set arguments
>
>
>
>
>
>
>
> Von: Viktor Bojović [mailto:viktor(dot)bojovic(at)gmail(dot)com]
> Gesendet: Samstag, 29. Januar 2011 09:28
> An: Andreas Gaab
> Betreff: Re: [SQL] aggregation of setof
>
>
>
> i have never used that type but maybe you can try this;
>
> -create function which returns text[], and takse setof text as argument (if
> possible)
>
> -reach every text[] in set of text[] using array index
>
> -return values using "return next" for each text in text[] which is in set
> of text[]
>
>
>
> On Fri, Jan 28, 2011 at 12:42 PM, Andreas Gaab <A(dot)Gaab(at)scanlab(dot)de> wrote:
>
> Hi all,
>
>
>
> I would like to write a query, which aggregates the results of
> regexp_matches(). The problem is that regexp_matches returnes setof text[]
> as documented even if I discard the global flag
> (http://www.postgresql.org/docs/8.4/static/functions-matching.html#FUNCTIONS-POSIX-REGEXP
> ). Thus resulting in an error when I try to aggregate the result:
>
>
>
> “
>
> SELECT array_accum(
>
> regexp_matches('foobarbequebazilbarfbonk', '(b[^b]+)(b[^b]+)')
>
> )
>
> -------------------------------
>
> ERROR:  set-valued function called in context that cannot accept a set
>
> ********** Fehler **********
>
> ERROR: set-valued function called in context that cannot accept a set
>
> SQL Status:0A000
>
> “
>
>
>
> Can I convert a ‚setof text[]‘ to a ‚text[]‘?
>
>
>
> Alternatively I could use a sub-select, but I am curious if there are other
> solutions around.
>
>
>
> Regards,
>
> Andreas
>
>
>
> ___________________________________________________________________________
>
>
>
> SCANLAB AG
>
> Dr. Andreas Simon Gaab
>
> Entwicklung • R & D
>
>
>
> Siemensstr. 2a • 82178 Puchheim • Germany
>
> Tel. +49 (89) 800 746-513 • Fax +49 (89) 800 746-199
>
> mailto:a(dot)gaab(at)scanlab(dot)de • www.scanlab.de
>
>
>
> Amtsgericht München: HRB 124707 • USt-IdNr.: DE 129 456 351
>
> Vorstand: Georg Hofner (Sprecher), Christian Huttenloher, Norbert Petschik
>
> Aufsichtsrat (Vorsitz): Dr. Hans J. Langer
>
> ___________________________________________________________________________
>
>
>
>
> --
> ---------------------------------------
> Viktor Bojović
> ---------------------------------------
> Wherever I go, Murphy goes with me

In response to

Responses

Browse pgsql-sql by date

  From Date Subject
Next Message Michael Gould 2011-01-31 13:40:24 fix uuid contrib module for Windows 64
Previous Message Pavel Stehule 2011-01-31 09:23:56 Re: aggregation of setof