Re: Problem after installing triggering function

To reproduce the problem, here is some simple steps to follow :

(1) create database named "tutorial"

(2) perform the following SQL query :

CREATE TABLE impressions_by_day (
advertiser_id SERIAL NOT NULL,
day DATE NOT NULL DEFAULT CURRENT_DATE,
impressions INTEGER NOT NULL,
PRIMARY KEY (advertiser_id, day)
);

CREATE OR REPLACE FUNCTION insert_table()
RETURNS void AS
$BODY$DECLARE
_impressions_by_day impressions_by_day;
BEGIN
INSERT INTO impressions_by_day(impressions ) VALUES(888) RETURNING * INTO _impressions_by_day;

RAISE NOTICE 'After insert, the returned advertiser_id is %', _impressions_by_day.advertiser_id;
END;$BODY$
LANGUAGE 'plpgsql' VOLATILE;
ALTER FUNCTION insert_table() OWNER TO postgres;

(3) create database named "tutorial_partition"

(4) perform the following SQL query :

CREATE TABLE impressions_by_day (
advertiser_id SERIAL NOT NULL,
day DATE NOT NULL DEFAULT CURRENT_DATE,
impressions INTEGER NOT NULL,
PRIMARY KEY (advertiser_id, day)
);

CREATE OR REPLACE FUNCTION insert_table()
RETURNS void AS
$BODY$DECLARE
_impressions_by_day impressions_by_day;
BEGIN
INSERT INTO impressions_by_day(impressions ) VALUES(888) RETURNING * INTO _impressions_by_day;

RAISE NOTICE 'After insert, the returned advertiser_id is %', _impressions_by_day.advertiser_id;
END;$BODY$
LANGUAGE 'plpgsql' VOLATILE;
ALTER FUNCTION insert_table() OWNER TO postgres;

CREATE TABLE impressions_by_day_y2010m1ms2 (
PRIMARY KEY (advertiser_id, day),
CHECK ( day >= DATE '2010-01-01' AND day < DATE '2010-03-01' )
) INHERITS (impressions_by_day);

CREATE INDEX impressions_by_day_y2010m1ms2_index ON impressions_by_day_y2010m1ms2 (day);

CREATE OR REPLACE FUNCTION impressions_by_day_insert_trigger()
RETURNS TRIGGER AS $$
BEGIN
IF ( NEW.day >= DATE '2010-01-01' AND NEW.day < DATE '2010-03-01' ) THEN
INSERT INTO impressions_by_day_y2010m1ms2 VALUES (NEW.*);
ELSE
RAISE EXCEPTION 'Date out of range. Something wrong with the impressions_by_day_insert_trigger() function!';
END IF;
RETURN NULL;
END;
$$
LANGUAGE plpgsql;

CREATE TRIGGER insert_impressions_by_day_trigger
BEFORE INSERT ON impressions_by_day
FOR EACH ROW EXECUTE PROCEDURE impressions_by_day_insert_trigger();

(5) execute

SELECT * FROM insert_table() on tutorial

We get

NOTICE: After insert, the returned advertiser_id is 1

(6) execute

SELECT * FROM insert_table() on tutorial_partition

We get

NOTICE: After insert, the returned advertiser_id is <NULL>

How is it possible to get advertiser_id is 1 too, in tutorial_partition?

Thanks!
Cheok