Transaction in plpgslq

I have got a plpgsql function:

CREATE FUNCTION nueva_llamada(integer, integer) RETURNS integer

as

DECLARE _operadora_id ALIAS FOR $1; _actividad_id ALIAS FOR $2; _contacto_id integer;

BEGIN
 -- BEGIN;
   SELECT min(id) INTO _contacto_id FROM contactos      WHERE contactos.operadora_id IS NULL AND contactos.actividad_id
= _actividad_id;
   UPDATE contactos SET operadora_id = _operadora_id WHERE id = _contacto_id;
 -- COMMIT;
 INSERT INTO llamadas (contacto_id, operadora_id, fecha)    VALUES (_contacto_id, _operadora_id, now());
 RETURN _contacto_id;
END

and it works right, but I need atomic execution from --BEGIN and
--COMMIT, and manual says it is not possible to have transactions in
PL/pgSQL procedures :-(

May be with LOCK TABLE?



--
Rafa Couto (caligari)
mailto:rafacouto@gmail.com
urgentes (sólo texto): rafa112@amena.com
PGP 0x30EC5C31 [E6BF 11EF FE55 38B1  CF7E 9380 58E5 9FA3]