From: ctrl@altonsys.com (ctrl)
Subject: help with Postgres function
Date: 16 Jun 2004 14:49:43 -0700
Organization: http://groups.google.com
Lines: 46
Message-ID: <46a31c4d.0406161349.38d3a34b@posting.google.com>
Content-Type: text/plain; charset=ISO-8859-1
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To: pgsql-sql@postgresql.org

Hello.
I'd appreciate any help with a function I'm writing.
I have a simple table like this:
CREATE TABLE websites ( 
id BIGSERIAL not null primary key,
domain character varying(256) NOT NULL,
last_fetch timestamp without time zone DEFAULT 'now()',
crawl_status smallint not null DEFAULT 1
);

and my function retrieves the next available row in this table, by age
(the oldest inserted and with status 1)
I have written this but I have problems with it...and also it doesn't
seems right to me...from coding style and performance point of view.

CREATE OR REPLACE FUNCTION getNextWebsiteForCrawl(integer) RETURNS
website AS '
DECLARE
my_record RECORD;
w website%rowtype;
count smallint;
BEGIN
 SELECT id, domain into my_record FROM websites WHERE crawl_status=1
AND date(last_fetch) > (current_timestamp - interval ''$1 days'')
 ORDER BY last_fetch LIMIT 1;
 select count(*) into count from my_record;
 if count > 0 then
 w.id := my_record.id;
 w.domain := my_record.domain;
 update websites set crawl_status=2 where id = my_record.id;
 end IF;
 return w;
END;
' LANGUAGE plpgsql;

The reason I have that IF is for when there are no more rows
available...
when I call this function (SELECT * FROM getNextWebsiteForCrawl(5))
I get an error:
WARNING:  Error occurred while executing PL/pgSQL function
getnextwebsiteforcrawl
WARNING:  line 8 at select into variables
ERROR:  parser: parse error at or near "(" at character 13

Could somebody good show me how to do it better?
Thanks a lot!