[Zope] q: How should I get a guaranteed unique id in Zope?

[Todd Graham]

Hey Joe,

What database are you using as the backend, does it support sequences?  This
is probably the best way to ensure referential integrity.

T


----- Original Message -----
From: Joe Block <jpb@ApesSeekingKnowledge.net>
To: Zope List <zope@zope.org>
Sent: Monday, January 14, 2002 6:34 PM
Subject: [Zope] q: How should I get a guaranteed unique id in Zope?


> I just discovered Zope a couple of weeks ago, and have started migrating
> a cgi based web application that I was writing in straight python to
> Zope both as a learning exercise and to take advantage of Zope's feature
> set.
>
> My problem is, I have several sql tables that I'm storing data in that I
> need to be able to have the same jobid in because I'm using the jobid to
> match which comments are attached to which jobs.  When I was using cgis,
> this was easy - I made a class that wrapped the following function
>
>          def makeID(self):
>                  idstring = "%s-%s.%s-%s" % (self.prefix, os.getpid(),
> time.time(), self.counter)
>                  self.counter = self.counter + 1
>                  return idstring
>
> and I could be guaranteed their uniqueness because prefix was the
> hostname of the server the cgi was running on, and the combination of
> the other 3 parts was unique per call to makeID.
>
> Now that I'm using Zope, the pid isn't unique any more, of course.  I
> don't want to store a counter in the database, because from some of the
> postings I saw in the last few days here I think it'll cause my db to
> grow for no reason as it stores unwanted undo information.  I also
> haven't figured out how to lock an object while I update properties
> yet.  I don't want to use an external file either, because the constant
> locking & unlocking seems likely to cause performance problems
> eventually.
>
> I have both _The Zope Book_ and _Zope Web Application Development and
> Content Management_ , and haven't found an answer to my problem in
> either book as yet.
>
> I'm running Zope 2.5.0b3 with Python 2.1.1 on Mac OS X 10.1.2
>
> Thanks,
>
> jpb
> --
> Joe Block <jpb@ApesSeekingKnowledge.net>
>
> Madness takes its toll. Please have exact change ready.
>
>
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