[Zope] dtml-tree and Z SQL methods

[Ragnar Beer]

Does anyone know how to display hierarchical content from SQL? I was 
hoping to find the answer in the "Secrets of working with the tree 
tag"-HOWTO but appearently it's not yet in there.

What I have in (My)SQL is a table with:
cont_id     - Unique ID (primary key) of a container
upper_id    - ID of the upper container or NULL
               (the container containing this container;)
description - text to be displayed describing the container

Ragnar Beer