nirasha,

As I said this is not format, to_char, to_date issue!

OK, look this one:

create table m (m_id int primary key, des varchar2(32));
create table d (d_id int primary key, another_id int, m_id int);
alter table d add constraints d_fk foreign key (m_id) references m(m_id);

insert into m values (1, 'TEST1');
commit;

select m.DES, count(d.d_id)
from m, d
where m.m_id = d.m_id(+)
and m.m_id = 1
group by m.DES
/

DES COUNT(D.ID)
-------------------------------- -----------
TEST1 0

select m.DES, count(d.d_id)
from m, d
where m.m_id = d.m_id(+)
and m.m_id = 1
and d.another_id = 100
group by m.DES
/

no rows selected