Re: Out parameters handling

On Sat, Mar 7, 2009 at 11:32 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Robert Haas <robertmhaas(at)gmail(dot)com> writes:
>> On Sat, Mar 7, 2009 at 9:08 AM, Rod Taylor <rod(dot)taylor(at)gmail(dot)com> wrote:
>>> It wouldn't be so bad if you could assign internal and external column names.
>
>> This is a good point.  Uglifying the parameter names is sort of OK for
>> input parameters, but is much more annoying for output parameters.
>
> How much of this pain would go away if we changed over to the arguably
> correct (as in Or*cle does it that way) scoping for names, wherein the
> parser first tries to match a name against column names of tables of the
> current SQL statement, and only failing that looks to see if they are
> plpgsql variables?

This would solve all of my conflicts correctly. I nearly always use
RETURN QUERY with OUT parameters.

An alternative would be the requirement to prefix out parameters with
"out", "export", or something similar, so the plain non-prefixed name
is never replaced.

"b" in the below is the table.

I hit this quite a bit since my historical table name might be
"foo_bar_baz" which is the same as the most relevant name for the out
parameter.

I've debated renaming all of my tables t_* on more than one occasion
as a workaround in applications which exclusively use functions to
access/write data.

create or replace function read_some_data_from_data_region(a integer,
out b integer) as $$
begin
SELECT col
INTO out.b
FROM b;

return;
end; $$ language plpgsql;