Count Hierarchical Data(Binary Tree) in MySQL?

[Manivel P]

Hi,

I have questing on counting leaf nodes of binary tree.

My tables looks like below.

+------+---------+----------+
| ID | LEFT_ID | RIGHT_ID |
+------+---------+----------+
| 1 | 2 | 3 |
| 2 | 4 | 5 |
| 3 | 6 | 7 |
| 4 | 8 | 9 |
| 5 | NULL | NULL |
| 6 | 10 | 11 |
| 7 | 12 | 13 |
| 10 | 14 | 15 |
| 11 | NULL | NULL |
| 12 | NULL | NULL |
| 13 | NULL | NULL |
| 14 | NULL | NULL |
| 15 | NULL | NULL |
| 8 | NULL | NULL |
| 9 | NULL | NULL |
+------+---------+----------+

using this data i want count total leaf's.

For example count of leaf is 14 for 1, 4 for 2, 8 for 3, etc..

If anybody have thoughts to get this count in mysql db.

thanks,
-Mani