Rafa Couto wrote:
I have got a plpgsql function:
-- 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;
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 :-(
OK - the WHOLE FUNCTION takes place within one transaction. So, in that
sense all changes are atomic.
However, if you want to prevent any changes to "contactos" in-between
those two statements you'll want additional locks. Read the chapter on
"concurrency control" for details. You might well want SELECT FOR UPDATE
(and also just ORDER BY id LIMIT 1 rather than using min(id)).
--
Richard Huxton
Archonet Ltd
---------------------------(end of broadcast)---------------------------
TIP 3: if posting/reading through Usenet, please send an appropriate
subscribe-nomail command to [EMAIL PROTECTED] so that your
message can get through to the mailing list cleanly
