Another post in the series ‘remember this SQL trick‘ 🙂

The within group clause can be used to merge multiple records into a single row. In the classic emp table with ename and deptno columns, the query is:

select
   deptno,
   listagg (ename, ',') 
WITHIN GROUP 
(ORDER BY ename) enames
FROM 
   emp
GROUP BY 
   deptno

The article below displays more ways of doing this, but the query above worked for me.
Oracle SQL: displaying multiple column values per row