Re: Re: postgres TODO

Tom Lane wrote:
>
> Alessio Bragadini <alessio(at)albourne(dot)com> writes:
> > Peter Eisentraut wrote:
> >>>> * Add function to return primary key value on INSERT
> >>
> >> I don't get the point of this. Don't you know what you inserted? For
> >> sequences there's curval()
>
> To get back to Peter's original question, you don't necessarily "know
> what you inserted" if you allow columns to be filled with default values
> that are calculated by complicated functions. A serial column is just
> the simplest example of that. Whether this situation is common enough
> to justify a special hack in INSERT is another question. I kinda doubt
> it. We already return the OID which is sufficient info to select the
> row again if you need it. Returning the primary key would be
> considerably more work for no visible gain in functionality...

It's definitely not a crucial functionality gain, IMO, but it is
nonetheless a gain when you consider that *every* pgsql developer on
the planet could then do something in one query that currently takes
two (plus the requisite error-handling code). A few other counter-
arguments for returning the autoincrement/serial/pkey:

1) it earns bad press w/r/t usability;
2) it is an FAQ on the lists;
3) it is an extremely common operation;
4) other DBs provide it;

Regards,
Ed Loehr