[Zope] help with zodb

[Jeff Hoffman]

On Thu, 2 Mar 2000, Garrett G. Hodgson wrote:

> thank you for your help.  forgive my being obtuse, but i'm still not
> getting it.

Turns out it was me that was being obtuse. See below.

> > Only one process can access a ZODB at a time. You have two. The first is
> > Zope, and the second is the external method.
> 
> ok.  by "a ZODB" do you mean that the call in my external method
> is trying to reopen the ZODB zope is using?  i'd assumed i was 
> crating another one, with a separate FileStorage.

This is the detail I did not notice, previously. I thought you were trying
to store objects in your Zope ZODB; I didn't notice that the filename you
were passing to FileStorage was not Data.fs.

Sorry.

[snip]

> so, one more try.  given the following external method:
> 
> import ZODB, ZODB.FileStorage
> 
> 
> def GetPeople( self ):
> 	"Return list of people in DB"
> 
> 	db = ZODB.DB( ZODB.FileStorage.FileStorage( 'TestDB.fs' ) )
> 	connection = db.open()
> 	root = connection.root()
> 	people = []
> 	for key in root.keys():
> 		people.append( root[ key ] )
> 	return people
> 
> if __name__ == '__main__':
> 	for person in GetPeople( None ):
> 		print person.name, 'is', person.age, 'years old'
> 
> 
> referenced from a DTML Method:
> 
> <dtml-in "GetPeople()">
> 	<dtml-var name> is <dtml-var age> years old.<br>
> </dtml-in>
> 
> when i restart zope and view the method, it works once, but shows
> no persons.  the second time, it fails with the traceback.

I don't understand why the problem is manifesting as it is, but I got your
code to work by modifying your code as follows:

- for key in root.keys():
-         people.append(root[key])
+ connection.close()
- return people

Opening a connection without closing it is a Bad Idea. I just can't figure
out what this has to do with the lock file on the database. I figured when
I closed the connection it was deleting the lock, but this is not so. So,
I remain confused. ;-)

> what do i change to make it work?

Hope this helps!

--Jeff

---
Jeff K. Hoffman                                         704.849.0731 x108
Chief Technology Officer                                mailto:jeff@goingv.com
Going Virtual, L.L.C.                                   http://www.goingv.com/