Thread: Inheritance of functions.

Inheritance of functions.

From
Andrzej Mazurkiewicz
Date:
Hello.
I have not got any help from HACKERS, SQL and GENERAL groups so I send my
problem to you. Could you send the clear indication whether lack of
inheritance of functions is a bug. If it is not, I would appreciate ANY
example showing inheritance of functions in postgres.
Thanks,
Regards,
Andrzej Mazurkiewicz


In Postgres Users Guide, CREATE TABLE section, the following is stated:

 Postgres automatically allows the created table to inherit functions on
tables above it in the inheritance hierarchy.

          Aside: Inheritance of functions is done according to the
conventions of the Common Lisp Object System (CLOS).

I have tried different constructs but I have not been able to create such a
function. Can anybody send me an example of a function that will be
inherited by inherited table? I. e.
create table A (
.
.
);

create function F ...

create table B (
..
) inherits (A);

Now I assume that I can somehow use function F on table B

The specific example is given below !!

Thank you,
Regards,
Andrzej Mazurkiewicz


-----Original Message-----
From:    Andrzej Mazurkiewicz
Sent:    27 paYdziernika 1999 18:09
To:    'pgsql-general@hub.org'
Subject:    RE: [GENERAL] FW: inheritance of functions

Hello.
Here is an example of my problem:

ccbslin2:~/lipa$ psql -c "drop database archimp0;" template1
DESTROYDB
ccbslin2:~/lipa$ psql -c "create database archimp0;" template1
CREATEDB
ccbslin2:~/lipa$ psql -f funinh1.sql archimp0
BEGIN WORK;
BEGIN
CREATE TABLE A (
        liczba float
);
CREATE
COMMIT WORK;
END

BEGIN WORK;
BEGIN
CREATE FUNCTION suma (A) RETURNS float
        AS 'SELECT $1.liczba AS suma;' LANGUAGE 'sql';
CREATE
COMMIT WORK;
END

BEGIN WORK;
BEGIN
CREATE TABLE B (
        liczwym float
) INHERITS (A)
;
CREATE
COMMIT WORK;
END

BEGIN WORK;
BEGIN
INSERT INTO A (liczba) VALUES (1.56);
INSERT 71414 1
COMMIT WORK;
END

BEGIN WORK;
BEGIN
INSERT INTO B (liczba, liczwym) VALUES (2.5, 3.2);
INSERT 71415 1
COMMIT WORK;
END

select liczba, suma(A) from A;
liczba|suma
------+----
  1.56|1.56
(1 row)

select liczba, suma(A) from A*;
liczba|suma
------+----
  1.56|1.56
   2.5| 2.5
(2 rows)

[Andrzej Mazurkiewicz]  --
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

select liczba, suma(B) from B; [Andrzej Mazurkiewicz]         !!!!!!!
ERROR:  Functions on sets are not yet supported [Andrzej Mazurkiewicz]
!!!!!!!

[Andrzej Mazurkiewicz]  --
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

EOF

----------------------------------------------------------------------------
--------------------------------------

After invoking psql:


archimp0=> select * from pg_proc where proname = 'suma';
proname|proowner|prolang|proisinh|proistrusted|proiscachable|pronargs|proret
set|prorettype|
proargtypes|probyte_pct|properbyte_cpu|propercall_cpu|proouti
n_ratio|prosrc                   |probin
-------+--------+-------+--------+------------+-------------+--------+------
---+----------+-------------------+-----------+--------------+--------------
+--------------+-------------------------+------
suma   |     302|     14|f       |t           |f            |       1|f
|       701|71393 0 0 0 0 0 0 0|        100|             0|             0|
100|SELECT $1.liczba AS suma;|-
(1 row)

archimp0=>

I am looking for working example !!!!!

Regards,
Andrzej Mazurkiewicz
    -----Original Message-----