Hi all,
I've to develop a multilevel marketing web app. In this Im facing an issue, please help me in this issue

MemberX
\/
child1 child2 child3 child4 child5 child6 child7
\/
child11 child22 child33 child44 child55 child66 child77

each child can have 7 childs and upto 7 levels.

my table design is as following

tree
-----

id
parent_id
position
level


id | parent_id | position | level
---------------------------------
2 | 1 | 0 | 1
3 | 1 | 1 | 1
4 | 1 | 2 | 1
5 | 1 | 3 | 1
6 | 2 | 1 | 1


My problem is how to find a vacant position for given parent.

eg: when member 2 (id=2) is adding a new member i've to add the new member 7 in to a vacant position
under him or under any of his descendants.
Is there any way find a vacacnt position ? Or any alternate database design for this purpose ?
Pls help...

Thanks & regards

There are several ways of handling this. If you know that you will have a max of 7 under each parent then you could add something as follows:

Parent: A
Children of A: AA, AB, AC, AD, AE, AF, AG
Child of AE: AEA, AEB, AEC, AED, AEF, AEG

and so on.
If you have more than 7 and this can be any number then there are other techniques which require an update of each record in the hierarchy giving it a unique number. I would stick to the easier option above if you are sure with the max 7.

Finding the MAX(id) FROM table WHERE parentid = {id_you_are_searching}
The next entry is the available one for selection.