To do something similar, you would have to fork the source code and implement the declarations with the same syntax, resulting in something like Postracle.
but it doesn't support syntax WITHING GROUP syntax. Probably there is not a possibility to implement it in extension without introducing a new kind of aggregate functions in core, or enhancing behaviour of ordered-set kind of aggregates.
I agree but I just would like to know if there is way to be compatible with Oracle syntax using aggregate features in PostgreSQL
Thanks.
Le 09/03/2026 à 23:05, Paul A Jungwirth a écrit : > On Mon, Mar 9, 2026 at 1:21 PM Pierre Forstmann > <pierre.forstmann@gmail.com> wrote: >> Hello, >> >> I can write a LISTAGG aggregate for: >> >> create table emp(deptno numeric, ename text); >> >> SELECT deptno, LISTAGG(ename, ','::text ORDER BY ename) AS employees >> FROM emp GROUP BY deptno ORDER BY deptno; >> >> I would like to know if is possible to create an aggregate LISTAGG that >> would work like in Oracle: >> >> SELECT deptno, >> listagg(ename, ',') WITHIN GROUP (ORDER BY ename) AS employees >> FROM emp >> GROUP BY deptno >> ORDER BY deptno; > I don't think you need a custom aggregate here. In Postgres you can say: > > select deptno, > string_agg(ename, ',' ORDER BY ename) AS employees > FROM emp > GROUP BY deptno > ORDER BY deptno; >
