Yes, Checkpoint class is defined in models package. bus.checkpoint_id has value (in both cases, I can see it in debug messages)
-Dmitry On Apr 21, 8:04 am, 风笑雪 <[email protected]> wrote: > Why you use models.Checkpoint? > Is the Checkpoint class defines in models package/module? > > If not, use this: > point_old = Checkpoint.all().filter("checkpoint_id=", > bus.checkpoint_id).get() > > And for the "'NoneType' object has no attribute 'checkpoint_id'", you should > check bus.checkpoint_id to ensure it's not None. > > 2009/4/21 Dmitry Kachaev <[email protected]> > > > > > I use following construction to lookup records from datastore: > > > point_old=models.Checkpoint.all().filter("checkpoint_id > > =", bus.checkpoint_id).get() > > > It works fine in most scenarios, but sometime I'm getting error like > > this: > > > 'NoneType' object has no attribute 'checkpoint_id' > > Traceback (most recent call last): > > File "/base/python_lib/versions/1/google/appengine/ext/webapp/ > > __init__.py", line 501, in __call__ > > handler.get(*groups) > > File "/base/data/home/apps/xxx/1.332943763447248076/tasks/ > > busupdate.py", line 22, in get > > self.update(bus) > > File "/base/data/home/apps/xxx/1.332943763447248076/tasks/ > > busupdate.py", line 45, in update > > self.check_points(bus) > > File "/base/data/home/apps/xxx/1.332943763447248076/tasks/ > > busupdate.py", line 86, in check_points > > logging.debug("found old checkpoint: %s" % > > (point_old.checkpoint_id)) > > AttributeError: 'NoneType' object has no attribute 'checkpoint_id' > > > Basically, get() returns None, but record I looked up is definitely in > > datastore. > > > I figured out and replaced this look up call with equivalent GQL call: > > > point_old = db.GqlQuery("SELECT * FROM Checkpoint WHERE > > checkpoint_id = %s" % (bus.checkpoint_id)).get() > > #point_old=models.Checkpoint.all().filter("checkpoint_id > > =", bus.checkpoint_id).get() > > > What is wrong? Those constructs should behave the same way, but they > > don't. Commented one is not returning a record, when GQL is returning > > single record, just fine. > > > Thanks, > > Dmitry --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en -~----------~----~----~----~------~----~------~--~---
