From: Richard Rosenberg <richrosenberg@earthlink.net>
Reply-To: Richard Rosenberg <richrosenberg@earthlink.net>
To: pgsql-sql@postgresql.org
Subject: polymorphic function in 7.4 vs. 8.3
Date: Thu, 11 Jun 2009 13:16:12 -0700
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I have the following setup which works great in version 8.3 but throws an 
error in 7.4:


CREATE TABLE atest1
(
  id integer NOT NULL,
  descr text,
  CONSTRAINT atest1_pkey PRIMARY KEY (id)
);


CREATE OR REPLACE FUNCTION test_trg()
  RETURNS "trigger" AS
'
DECLARE
    any_rec wfsys.atest1;
    
BEGIN
any_rec.id := NEW.id;
any_rec.descr := NEW.descr;
select into any_rec * from dd_test(any_rec);
--any_rec := dd_test(any_rec);
RETURN any_rec;
END;
'
  LANGUAGE 'plpgsql' VOLATILE;


CREATE OR REPLACE FUNCTION dd_test(anyelement)
  RETURNS record AS
'
DECLARE
    any_rec alias for $1;
    some_row record;
BEGIN
    some_row := any_rec;
    if some_row.id < 0 then
        raise notice ''id is < 0!'';
        some_row.descr := ''some other value'';
    end if;
RETURN some_row;
END;
'
  LANGUAGE 'plpgsql' VOLATILE;

CREATE TRIGGER trg_atest1
  BEFORE INSERT
  ON atest1
  FOR EACH ROW
  EXECUTE PROCEDURE test_trg();

Finally, firing the trigger like so:

insert into wfsys.atest1 values(123, 'some text');

Gives the following error:

ERROR:  column "any_rec" does not exist
CONTEXT:  PL/pgSQL function "test_trg" line 7 at select into variables


********** Error **********

ERROR: column "any_rec" does not exist
SQL state: 42703
Context: PL/pgSQL function "test_trg" line 7 at select into variables


It works great on 8.3 (my dev server),  but throws the error on the machine I 
am forced to work with, which is running version 7.4. I realize that 
polymorphic functions were pretty new in v7.4, is there a workaround or am I 
making a silly mistake? Or both? 

Incidentally, I get the same error when I change the polymorphic function's 
argument from "anyelement" to "wfsys.atest1" so it seems that it is occurring 
in the trigger function.  Thanks for any help.

Richard