[Zope] more on SQL tree structures.

[Anthony Baxter]

I've got a db table that's essentially storing a tree of objects - 

  (
    obj_id int,
    parent_id int,
    name varchar
  )

I've got this working with the #tree display fine, with the help
of the previous discussions on zope-list (thank god I index my
mail spool)
 
The next question is a bit trickier - Given an obj_id, I want to 
display (in zope) the list of parent_ids of it back to the root 
object - any ideas on the best way to do this loop?

I can always just do it in an external method, but this seems like
cheating to me. 

Anthony