Support for "nested sets" and PHP (Re: Recursive select)

--CELKO-- schrieb:
> The usual example of a tree structure in SQL books is called an
> adjacency list model and it looks like this:

> Another way of representing trees is to show them as nested sets. 

Hello,

I thought a while about those nested sets to avoid recursive selects.
Made a few functions. Some of the expensive stuff seems to be solved
by introducing a 3rd column called "lvl".

If you are interested in, you can find it at 
 http://www.net-one.de/~ks/WOoK/

by taking a look at "The PostrgreSQL side". Celko's original text is
also there.

Some stuff may be interesting for using PHP to edit PostgreSQL's
tables. But that part is incomplete, yet.

I'd be happy to get your thoughts to improve the handling (and my
understanding) of "nested sets".

Bye,
Knut Sübert