From: Luis Sousa <llsousa@ualg.pt>
To: Stefano Vita Finzi <stefano.vita@pronesis.it>
Cc: pgsql-sql@postgresql.org
Subject: Re: plpgsql recursion
Date: Wed, 28 May 2003 10:03:42 +0100
Message-ID: <3ED47B6E.6010209@ualg.pt> (raw)
In-Reply-To: <01a601c31ef0$4a628220$0600a8c0@stefano>
References: <01a601c31ef0$4a628220$0600a8c0@stefano>
Can you post the recursion function that you use on this case to get out
the information from the table ?
Thanks,
Luis Sousa
Stefano Vita Finzi wrote:
>Greetings!
>I have a table like:
>
>node parent
> 1 2
> 2 3
> 3 4
>
>Since i traverse this table with a recursive function, i want to avoid
>infinite recursion loop. I have wrote a function to check that a new record
>does not create a circular dependency. The function i wrote is as follow:
>
>CREATE OR REPLACE FUNCTION dba_test(INTEGER,INTEGER) RETURNS TEXT AS '
> DECLARE
> traversing ALIAS FOR $1;
> testing ALIAS FOR $2;
> t_rec RECORD;
> BEGIN
> FOR t_rec IN SELECT node,parent FROM dba_test WHERE parent = traversing
>LOOP
> IF t_rec.node = testing THEN
> RETURN ''Circular'';
> ELSE
> PERFORM dba_test(t_rec.node,testing);
> END IF;
> END LOOP;
> RETURN ''ok'' || testing::text;
> END;
>' LANGUAGE 'plpgsql';
>
>I would use this function BEFORE inserting the new row. But if i try SELECT
>dba_test(4,1); i don't have the result i expect. Can i you give me an hint
>where am i wrong?
>
>Thank you!
>
>Stefano Vita Finzi
>kluge@despammed.com
>
>
>---------------------------(end of broadcast)---------------------------
>TIP 1: subscribe and unsubscribe commands go to majordomo@postgresql.org
>
>
>
>
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-sql@postgresql.org
Cc: llsousa@ualg.pt, stefano.vita@pronesis.it
Subject: Re: plpgsql recursion
In-Reply-To: <3ED47B6E.6010209@ualg.pt>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox