Am Mittwoch, 13. April 2005 12:19 schrieb Pierre-Yves Delens:
> Bonjour,

Guten Tag,

> I'm developing my first ZODB app (without Zope).
> I need to display sorted items from a BTree.
> Sorting should happen by one of the fields value, not by key order.

You can use "decorate sort undecorate". There are some examples in 
the python cookbook. 

> - Is IndexedCatalog the good solution ?

You don't need indexedCatalog for sorting. If your
whole btree fits into memory you can use it like a python 

I looked at IndexedCatalog, but diceded to use may own 
Catalog which implements a small subset of the Index-API
of Zope2. IndexedCatalog is more implicit than explicit.

If I could do a rewrite of my app, I would have a look at
the indexes of Zope3.

Building simple indexes with btrees is not dificult:
Just map the value of your object to the ID of your object:["Pierre"]=.... # Every object has an integer ID in my app.
Be sure to write unittests, which check that the (redundant) data of
the catalog don't get out of sync.


Thomas GŁttler, TBZ-PARIV GmbH, Bernsdorfer Str. 210-212, 09126 Chemnitz
Tel.: 0371/5221217 Fax:  0371/5221216

For more information about ZODB, see the ZODB Wiki:

ZODB-Dev mailing list  -

Reply via email to