PostgreSQL Inheritanced Tabla siempre vuelven Fila Con El valor nulo

Question

Me refiero a http://www.if-not-true-then-false.com/2009/11/howto-create-postgresql-table-partitioning-part-1/

Para reproducir el problema, aquí es algunos pasos simples a seguir:

(1) crear base de datos llamada "tutorial"

(2) realizar la siguiente consulta SQL:

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) crear base de datos llamada "tutorial_partition"

(4) realizar la siguiente consulta SQL:

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) Ejecutar

SELECT * FROM insert_table() on tutorial

Tenemos

AVISO: Después de inserción, el ADVERTISER_ID devuelto es 1

(6) Ejecutar

SELECT * FROM insert_table() on tutorial_partition

Tenemos

AVISO: Después de inserción, el ADVERTISER_ID devuelto es

¿Cómo es posible conseguir ADVERTISER_ID es demasiado 1, en tutorial_partition?

Answer 1

El gatillo está pasando NULL espalda, que indica al INSERT que ninguna acción se va a realizar. Dado que no se realiza ninguna acción, el regreso * vuelve cláusula nada. No vas a ser capaz de interceptar (y anulación) INSERT y Uso de regresar por la misma operación y conseguir algo significativo.