Re: function to operate on same fields, different records?

will trillich <will@serensoft.com> writes:
> i've tried
>     create function gpa(OPAQUE) ....
> and psql tells me it successfully
>     CREATED
> something, but
>     \df
> shows no such function.

I believe \df suppresses opaque-argument functions, on the theory that
they're probably just I/O functions.  But OPAQUE won't do you any good
anyway unless you code the function in C.

> what arg to i specify to allow varying records (with a subset of
> exactly-the-same-names field subset) to be passed to a function?

Inheritance seems to work for this in current sources:

regression=# create table p1 (f1 int);
CREATE
regression=# create table p2 (f2 int) inherits (p1);
CREATE
regression=# create function getf1(p1) returns int as '
regression'# select $1.f1' language 'sql';
CREATE
regression=# insert into p1 values(1);
INSERT 1030276 1
regression=# insert into p2 values(11,22);
INSERT 1030277 1
regression=# select getf1(p1) from p1;
 getf1
-------
     1
    11
(2 rows)

regression=#

            regards, tom lane