[Zope] Help: Recursive querying

Stephan Richter SRichter@ixl.com
Sat, 7 Aug 1999 09:50:56 -0500


Hello,

it is me again. I am finally at a point where I try to write my first
application in Zope. My goal is to write a threaded Discussion Board.
I did one before in Python using CGIs.
Here is the supporting table in PostGreSQL:

id	int4
pid	int4
date	datetime
title	varchar(40)
body	text

All messages that have pid 0 are root messages. The pid points at another row
in the same table.
It is very easy to write a recursive function to view a tree or a subtree of
the message board. I wrote all all necessary Z SQL Methods. 
Here my problem: I do not know how to write recursive functions in Zope using
the Z SQL Methods and external methods. Additional, to make it even harder, I
want to use the tree tag to display the message tree.
Here my Z SQL Method:
ID:		qry_msgs_by_pid
Title:		Query: Get all messages that the Parent
Connection id:	PyGreSQL_database_connection
Arguments:	pid:int
Query template:	select *
		from msg
		where
		<!--#sqltest pid column=pid type=int-->

Can someone please help my out. I believe I still have some troubles
understanding the philosophy of Zope, since I still think in CGI terms. :)
I would love to write all my web applications in Zope. I read all the
tutorials, but some of the examples are not general ot detailed enough to
understand the "kernel" of DTML and Zope. 

Thank you so very much for your help.

stephan
--
Stephan Richter
iXL - Software Designer and Engineer