PostgreSQL Inheritanced表总是返回行空值
-
23-09-2019 - |
题
我指的是 http://www.if-not-true-then-false.com/2009/11/howto-create-postgresql-table-partitioning-part-1/
重现的问题,这里是一些简单的步骤如下:
(1)创建数据库,名为"教程"
(2)执行以下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)创建数据库名为"tutorial_partition"
(4)执行以下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)执行
SELECT * FROM insert_table() on tutorial
我们得到
注意:之后插入、返回advertiser_id是1
(6)执行
SELECT * FROM insert_table() on tutorial_partition
我们得到
注意:之后插入、返回advertiser_id是
怎么可能获得advertiser_id是1也是如此,在tutorial_partition?
解决方案
触发回空,其表明的插入,不采取行动是可以进行。由于没有采取行动执行,返回*条款返回什么都没有。你就不能拦截(和复盖)插入 和 使用返回的相同的操作和获得任何有意义的。
不隶属于 StackOverflow