[ZODB-Dev] Convert a ZODB 3.2 -> ZODB 3.3

[Jeremy Hylton]

On Thu, 7 Oct 2004 10:57:51 -0300, Christian Robottom Reis
<kiko at async.com.br> wrote:
> On Thu, Oct 07, 2004 at 09:31:20AM -0400, Chris Cioffi wrote:
> > I've got a stand alone ZODB app.  I can create new file storage files
> > no problem, but now I need to access the data from an older v3.2 file
> > storage file and I'm getting the error:
> >
> > No handlers could be found for logger "ZODB.FileStorage"
> > C:\Python23\Lib\site-packages\Persistence\__init__.py:25: UserWarning:
> > Couldn't import the ExtensionClass-based base class
> > ...
> 
> Well, it seems you have an ExtensionClass-based class stored in it. I
> haven't actually run into this problem myself but I understand you might
> have.
> 
> I'm not sure how to advise you here; Tim probably knows more about this
> than I do. I can explain what the problem is though: one or more
> instances saved in your ZODB file inherits from Persistence.Persistent
> (hardly surprising), and Persistent is gone from 3.3, replaced by a
> non-ExtensionClass-based Persistent class.

I think what you need to do is modify the source code to refer to the
new persistent base class, then you should be able to load the old
database.  There's a terse description of the issue deep down in the
NEWS file under the heading "What's new in ZODB3 3.3 alpha 2"
(You would almost like to have a brand-new news file for the final
release that summarized all the changes in the alphas and betas.)

Jeremy