Re: [PATCH] GROUP BY ALL

On 26.09.25 16:11, Tom Lane wrote:
> Peter Eisentraut <peter(at)eisentraut(dot)org> writes:
>> The initially proposed patch appears to have the right idea overall.
>> But it does not handle more complex cases like
>> SELECT a, SUM(b)+a FROM t1 GROUP BY ALL;
>
>> (For explanation: GROUP BY ALL expands to all select list entries that
>> do not contain aggregates. So the above would expand to
>> SELECT a, SUM(b)+a FROM t1 GROUP BY a;
>> which should then be rejected based on the existing rules.)
>
> I thought I understood this definition, up till your last
> comment. What's invalid about that expanded query?
>
> regression=# create table t1 (a int, b int);
> CREATE TABLE
> regression=# SELECT a, SUM(b)+a FROM t1 GROUP BY a;
> a | ?column?
> ---+----------
> (0 rows)

This was a sloppy example. Here is a better one:

create table t1 (a int, b int, c int);

select a, sum(b)+c from t1 group by all;

This is equivalent to

select a, sum(b)+c from t1 group by a;

which would be rejected as

ERROR: column "t1.c" must appear in the GROUP BY clause or be used
in an aggregate function