Re: Trigger to keep track of table changes

n the end I solved this through 'Divide and conquer' - I split the trigger
into three parts and now it works (though I am not sure yet why the
original trigger does not work):

CREATE OR REPLACE FUNCTION taxon_history_delete() RETURNS trigger
AS $BODY$BEGIN
IF TG_OP = 'DELETE' THEN
INSERT INTO history.taxon(operacao, data, tecnico, original_oid, taxon)
VALUES ('DELETE', current_timestamp, current_user, old.oid, old.taxon);
RETURN old;
END IF;END;$BODY$
LANGUAGE plpgsql;
CREATE OR REPLACE FUNCTION taxon_history_update() RETURNS trigger AS $BODY$BEGIN
IF TG_OP = 'UPDATE' THEN
INSERT INTO history.taxon(operacao, data, tecnico, original_oid, taxon)
VALUES ('UPDATE', current_timestamp, current_user, old.oid, old.taxon);
RETURN old;
END IF;END;$BODY$
LANGUAGE plpgsql;
CREATE OR REPLACE FUNCTION taxon_history_insert() RETURNS trigger AS $BODY$BEGIN
IF TG_OP = 'INSERT' THEN
INSERT INTO history.taxon(operacao, data, tecnico, original_oid, taxon)
VALUES ('INSERT', current_timestamp, current_user, new.oid, new.taxon);
RETURN new;
END IF;END;$BODY$
LANGUAGE plpgsql;
create TRIGGER taxon_history_delete
Before DELETE ON taxonFOR EACH ROW EXECUTE PROCEDURE taxon_history_delete();
create TRIGGER taxon_history_update
Before UPDATE ON taxonFOR EACH ROW EXECUTE PROCEDURE taxon_history_update();
create TRIGGER taxon_history_insert
AFTER INSERT ON taxonFOR EACH ROW EXECUTE PROCEDURE taxon_history_insert();

ALT SHN <i(dot)geografica(at)alt-shn(dot)org> escreveu no dia sábado, 22/06/2019 à(s)
11:33:

> I am trying to create a trigger (Postgres 9.6) to track changes made to a
> table. This is my approach:
>
> CREATE OR REPLACE FUNCTION taxon_history() RETURNS trigger AS
> $BODY$
> BEGIN
> IF TG_OP = 'DELETE' THEN
> INSERT INTO history.taxon(operacao, "data", tecnico, original_oid,
> taxon)
> VALUES ('DELETE', current_timestamp, current_user, old.oid, old.taxon);
> RETURN old;
>
> ELSIF TG_OP = 'UPDATE' THEN
> INSERT INTO history.taxon(operacao, "data", tecnico, original_oid,
> taxon)
> VALUES ('DELETE', current_timestamp, current_user, old.oid, old.taxon);
> RETURN old;
>
> ELSIF TG_OP = 'INSERT' THEN
> INSERT INTO history.taxon(operacao, "data", tecnico, original_oid,
> taxon)
> VALUES ('INSERT', current_timestamp, current_user, new.oid, new.taxon);
> RETURN old;
> END IF;
> END;
> $BODY$
> LANGUAGE plpgsql;
>
> CREATE TRIGGER history_taxon
> AFTER INSERT OR UPDATE OR DELETE ON taxon
> FOR EACH ROW EXECUTE PROCEDURE taxon_history();
>
> However when something changes in the `taxon` table, no record is added to
> the `taxon_history` table. I also don´t get any error message so I am in
> the dark on why nothing is happening. What am I doing wrong?
>
> --
> ---------------------------------------------------------------
>
>
> *Sociedade de História Natural*
> Departamento de Informação Geográfica
> Polígono Industrial do Alto do Amial
> Pav.H02 e H06
> PORTUGAL
>
> i(dot)geografica(at)alt-shn(dot)org <laboratorio(at)alt-shn(dot)org>
> www.shn.pt
> www.alt-shn.blogspot.com
> Facebook <https://www.facebook.com/SociedadeDeHistoriaNatural?ref=hl>
>
>

--
---------------------------------------------------------------

*Sociedade de História Natural*
Departamento de Informação Geográfica
Polígono Industrial do Alto do Amial
Pav.H02 e H06

i(dot)geografica(at)alt-shn(dot)org <laboratorio(at)alt-shn(dot)org>
www.shn.pt
www.alt-shn.blogspot.com
Facebook <https://www.facebook.com/SociedadeDeHistoriaNatural?ref=hl>

TLM: 964138188