Re: LISTAGG à la Oracle in PostgreSQL

[Pierre Forstmann]

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.forstm...@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;