sql - Hierarchical Query: Get the direct children count for each node -

i new hierarchical queries , have gone through of posts on it.

i have query improve.

my scenario this:

sample ------- id,   name,   parent_id   

table data follows:

id    name   parent_id   ----------------------- 1        (null)   2     b    1     3     c    2     4     d    1     

i want result this:

id    name    parent_id    is_leaf    level   direct_children_count   ------------------------------------------------------------------- 1             (null)       0         1      2 2      b        1            0         2      1 3      c        2            1         3      0 4      d        1            1         2      0 

i wrote following query gives columns except direct_children_count

select id, name, parent_id, connect_by_leaf is_leaf, level sample  start parent_id = null connect prior id = parent_id 

there many posts on how count of children of node(not direct children), not applicable me because

1.i want direct children count.
2.if possible want achieve without using joins.

i have no clue how direct children count column value each of records. there anyway direct_children_count using hierarchical queries?