oracle function time string to time string

from_a_to_b

create or replace function func_from_str_to_date_str(
                                    a_date_str    in varchar2,
                                    b_date_format in varchar2,
                                    a_date_format in varchar2 default 'yyyy-MM-dd hh24:mi:ss')
return varchar2 as
  v_result         varchar2(100);
begin

  select to_char(
            to_date(a_date_str, a_date_format),
            b_date_format
         )
    into v_result
  from dual;

  return v_result;

exception
  when others then
    dbms_output.put_line('code:' || sqlcode);
    dbms_output.put_line('errm:' || sqlerrm);
    dbms_output.put_line('lineno:' || dbms_utility.format_error_backtrace);
    return('');
end;

 

select 
    func_from_str_to_date_str('2020-12-03 11:00:37', 'hh24:mi')
from dual