Oracle 11g Release 2

By using db<>fiddle, you agree to license everything you submit by Creative Commons CC0.

create table ACOUNT(MONEY_c VARCHAR2(1 BYTE))
insert into ACOUNT values('1')
1 rows affected

insert into ACOUNT values('2')
1 rows affected

select MONEY_c
       , to_char(MONEY_c, 'FM999G999G999G999D99', 'NLS_NUMERIC_CHARACTERS='',.''')  
from ACOUNT
where MONEY_c is not null


MONEY_C
TO_CHAR(MONEY_C,'FM999G999G999G999D99','NLS_NUMERIC_CHARACTERS='',.''')


1
1,

2
2,


insert into ACOUNT values('A')
1 rows affected

select MONEY_c
       , to_char(MONEY_c, 'FM999G999G999G999D99', 'NLS_NUMERIC_CHARACTERS='',.''')  
from ACOUNT
where MONEY_c is not null
ORA-01722: invalid number