get one value from multiple values in Oracle SQL

I tried the below query which returns two values but i need to get one value separated with ','. For example the query should return result :

TRPT,PRLD

Below is the query i tried:

SELECT     
    LISTAGG(T_NAME, ',') WITHIN GROUP (ORDER BY T_NAME) "ListValues"
FROM TST_TBL where T_DATE > sysdate-1 
GROUP BY T_NAME

It returns:

ListValues
    TRPT
    PRLD

Solution 1:

Remove the GROUP BY clause, it causes your "problems".

SQL> with tst_tbl (t_name, t_date) as
  2    (select 'TRPT', sysdate from dual union all
  3     select 'PRLD', sysdate from dual
  4    )
  5  SELECT
  6      LISTAGG(T_NAME, ',') WITHIN GROUP (ORDER BY T_NAME) "ListValues"
  7  FROM TST_TBL where T_DATE > sysdate-1
  8  /

ListValues
--------------------
PRLD,TRPT

SQL>