-----Original Message----- From: Philip Aylesworth <phila@purpleduck.com> To: zope@zope.org <zope@zope.org> Date: Wednesday, September 22, 1999 8:12 AM Subject: [Zope] Where is the Z Class Tutorial?

In the excellent "How-To: Z Catalog Tutorial" Amos refers us to the "Z Class Tutorial". I think Z Classes are just what I want, but I can't find it. Does anyone know where it is?

http://www.zope.org:8080/Documentation/Reference/ZClasses (I found this under Documentation -> Developer Reference on zope.org)

I started to look at Gadfly but then I came across mention of Z Classes.

Are they robust enough for a couple of thousand entries?

Personally, I really enjoy working with ZClasses instead of a standard relational database. I have no reason to think that they won't scale to a couple thousand entries. Right now, I have a ZClass container that contains about 25 ZClass containers that contain about 550 ZClasses that contain about 750 ZClass instances. In total, my ZODB probably has 1400-1500 ZClass instances and I have no complaints. Between the convenience of direct traversal to objects and the zippy searching of ZCatalog, it all works great!

Can I cross reference say contacts and companies stored in two separate Z Classes?

Though there have been a couple requests for it, there is no property type that can directly link one object to another. There are certainly a few ways to accomplish a similar result. In the "contacts" and "companies" example, if there is no chance of a contact being with more than one company, you can do this: Company (ZClass that inherits from ObjectManager so that it can contain other objects) Contact (ZClass) Then, if you refer to a Contact object, you can get to the company by using PARENTS[1]. Kevin