Write query to convert string in ascending order

Input:

ORACLE

Output:

ACELOR

STEP1:

with d as (select 'ORACLE' c FROM DUAL)

           select c from d

           connect by level<=length(c);

Output:

ORACLE
ORACLE
ORACLE
ORACLE
ORACLE
ORACLE

STEP2: 

 with d as (select 'ORACLE' c FROM DUAL)

           select substr(c,level,1) e from d

           connect by level<=length(c);

Output:

O
R
A
C
L
E

STEP3:

with d as (select 'ORACLE' c FROM DUAL)

           select listagg(e,'') within group(order by e asc) col

           from (select substr(c,level,1) e from d

            connect by level<=length(c));

Output:

ACELOR