Altering parent table breaks child table defaults
| От | Ovid |
|---|---|
| Тема | Altering parent table breaks child table defaults |
| Дата | |
| Msg-id | 1381157471.86442.YahooMailNeo@web120003.mail.ne1.yahoo.com обсуждение исходный текст |
| Ответы |
Re: Altering parent table breaks child table defaults
(Adrian Klaver <adrian.klaver@gmail.com>)
|
| Список | pgsql-general |
Hi all,
This problem has also been posted to Stack Overflow. http://stackoverflow.com/questions/19227920/altering-a-parent-table-in-postgresql-8-4-breaks-child-table-defaults
The problem: In Postgresql 8.4 (not tested on other versions), if table `temp_person_two` inherits from`temp_person`, default column values on the child table are ignored if the *parent* table is altered.
How to replicate (these don't need to be temporary tables. I made them temporary for your cut-n-paste convenience):
First, create table and a child table. The child table should have one column that has a default value.
CREATE TEMPORARY TABLE temp_person (
person_id SERIAL,
name VARCHAR
);
CREATE TEMPORARY TABLE temp_person_two (
has_default character varying(4) DEFAULT 'en'::character varying NOT NULL
) INHERITS (temp_person);
Next, create a trigger on the parent table that copies its data to the child table (I know this appears like bad design, but this is a minimal test case to show the problem).
CREATE FUNCTION temp_person_insert() RETURNS trigger
LANGUAGE plpgsql
AS '
BEGIN
INSERT INTO temp_person_two VALUES ( NEW.* );
RETURN NULL;
END;
';
CREATE TRIGGER temp_person_insert_trigger
BEFORE INSERT ON temp_person
FOR EACH ROW
EXECUTE PROCEDURE temp_person_insert();
Then insert data into parent and select data from child. The data should be correct.
INSERT INTO temp_person (name) VALUES ('ovid');
SELECT * FROM temp_person_two;
person_id | name | has_default
-----------+------+-------------
1 | ovid | en
(1 row )
Finally, alter the parent table by adding a new, unrelated column. Attempt to insert data and watch a "not-null constraint" violation occur:
ALTER TABLE temp_person ADD column foo text;
INSERT INTO temp_person(name) VALUES ('Corinna');
ERROR: null value in column "has_default" violates not-null constraint
CONTEXT: SQL statement "INSERT INTO temp_person_two VALUES ( $1 .* )"
PL/pgSQL function "temp_person_insert" line 2 at SQL statement
My version:
testing=# select version();
version
-------------------------------------------------------------------------------------------------------
PostgreSQL 8.4.17 on x86_64-pc-linux-gnu, compiled by GCC gcc-4.4.real (Debian 4.4.5-8) 4.4.5, 64-bit
(1 row)
Cheers,
Ovid
--
IT consulting, training, international recruiting
http://www.allaroundtheworld.fr/.
Buy my book! - http://bit.ly/beginning_perl
Live and work overseas - http://www.overseas-exile.com/
IT consulting, training, international recruiting
http://www.allaroundtheworld.fr/.
Buy my book! - http://bit.ly/beginning_perl
Live and work overseas - http://www.overseas-exile.com/
В списке pgsql-general по дате отправления: