CREATE OR REPLACE FUNCTION my_upsert()
  RETURNS trigger AS
$BODY$DECLARE
_tovar_count integer;

BEGIN
	SELECT COUNT(*) INTO _tovar_count FROM _tovar WHERE article=new.article;
	IF _tovar_count=0 THEN
		RETURN NEW;
	ELSIF _tovar_count=1 THEN
		IF 'name'<>new.name THEN
			UPDATE _tovar SET name=new.name WHERE id=id;
		END IF;
		IF 'lastdate'<=new.lastdate THEN
			UPDATE _tovar SET lastdate=new.lastdate WHERE id=id;
		END IF;
	END IF;
	RETURN NULL;
END;$BODY$
  LANGUAGE plpgsql VOLATILE
  COST 100;
ALTER FUNCTION my_upsert()
  OWNER TO postgres;

IF 'lastdate'<=new.lastdate THEN

WHERE (article=new.article) AND (distrib=new.distrib);

IF 'name'<>new.name THEN

CREATE OR REPLACE FUNCTION my_upsert()
  RETURNS trigger AS
$BODY$DECLARE
	_tovar_found record;
	_tovar_count Integer;
BEGIN
	SELECT * INTO _tovar_found FROM _tovar WHERE (article=new.article) AND (distrib=new.distrib);
	SELECT COUNT(*) INTO _tovar_count FROM _tovar WHERE (article=new.article) AND (distrib=new.distrib);
	IF _tovar_count=0 THEN
		RETURN NEW;
	ELSIF _tovar_count=1 THEN
		IF _tovar_found.name<>new.name THEN
			UPDATE _tovar SET name=new.name WHERE id=_tovar_found.id;
		END IF;
		IF _tovar_found.lastdate<=new.lastdate THEN
			IF _tovar_found.cost<>new.cost THEN
				UPDATE _tovar SET lastdate=new.lastdate, cost=new.cost WHERE id=_tovar_found.id;
			ELSE
				UPDATE _tovar SET lastdate=new.lastdate WHERE id=_tovar_found.id;
			END IF;
		END IF;
	END IF;
	RETURN NULL;
END;$BODY$
  LANGUAGE plpgsql VOLATILE
  COST 100;
ALTER FUNCTION my_upsert()
  OWNER TO postgres;

SELECT * INTO _tovar_found FROM _tovar WHERE (article=new.article) AND (distrib=new.distrib);