Re: aggregation of setof - Mailing list 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.stehule@gmail.com] 
Gesendet: Montag, 31. Januar 2011 10:24
An: Andreas Gaab
Cc: pgsql-sql@postgresql.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.Gaab@scanlab.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.bojovic@gmail.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.Gaab@scanlab.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
>
>
>
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>
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>
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> --
> ---------------------------------------
> Viktor Bojović
> ---------------------------------------
> Wherever I go, Murphy goes with me