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

On Mon, Apr 02, 2001 at 10:21:34AM -0400, Tom Lane wrote:
> 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)

ding! light comes on ... never thought of that. mucho cool, mucho
thanks! lots of new exploring to delve into now...

--
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will@serensoft.com
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