Re: [PATCH] GROUP BY ALL

On Mon, 22 Jul 2024 at 17:34, David G. Johnston <david(dot)g(dot)johnston(at)gmail(dot)com>
wrote:

> On Mon, Jul 22, 2024 at 1:55 PM David Christensen <david(at)pgguru(dot)net>
> wrote:
>
>> I see that there'd been some chatter but not a lot of discussion about
>> a GROUP BY ALL feature/functionality. There certainly is utility in
>> such a construct IMHO.
>>
>> Still need some docs; just throwing this out there and getting some
>> feedback.
>>
>>
> I strongly dislike adding this feature. I'd only consider supporting it
> if it was part of the SQL standard.
>
> Code is written once and read many times. This feature caters to
> the writer, not the reader. And furthermore usage of this is prone to be
> to the writer's detriment as well.
>

And for when this might be useful, the syntax for it already exists,
although a spurious error message is generated:

odyssey=> select (uw_term).*, count(*) from uw_term group by uw_term;
ERROR: column "uw_term.term_id" must appear in the GROUP BY clause or be
used in an aggregate function
LINE 1: select (uw_term).*, count(*) from uw_term group by uw_term;
^

I'm not sure exactly what's going on here — it's like it's still seeing the
table name in the field list as only a table name and not the value
corresponding to the whole table as a row value (But in general I'm not
happy with the system's ability to figure out that a column's value has
only one possibility given the grouping columns). You can work around:

odyssey=> with t as (select uw_term, count(*) from uw_term group by
uw_term) select (uw_term).*, count from t;

This query works.