if you want transactions you need to do : with transaction.atomic():
like described here: https://docs.djangoproject.com/en/dev/topics/db/transactions/ Am Mittwoch, 22. Mai 2013 10:40:15 UTC+2 schrieb Christian Schmitt: > > In Django the normal behavior should be that when you do a save() it will > automatically commit() your query's to the database. > so that in obj.save() you should just could access the pk with obj.idafter > you did a obj.save(). > If you want to maybe stop the commit you need to do a obj = > obj.save(commit=False), then you could add some things to your obj and > commit/save it later. > But as i understood you already do a obj.save() but it doesn't commit > correctly? Maybe you should just try a PostgreSQL database for testing, > since I'm not having trouble looking up objects after i saved it. > > I often do things like: > obj.save() > return HttpResponseRedirect(reverse('view', {'pk': obj.id})) > and i never run into any exception > > > Am Dienstag, 21. Mai 2013 23:20:53 UTC+2 schrieb Chris Conover: >> >> Calling transaction.commit() after object.save results in >> a TransactionManagementError. I mentioned at the end that I am using MySQL >> (5.5.27). The issue is not that the Gearman workers are having trouble >> saving their transactions, it's that they are having trouble looking up the >> incoming object. I'm assuming the view and workers are separate >> transactions since I don't see how they could be connected -- though I'm >> looking into this. >> >> On Tuesday, May 21, 2013 1:05:54 PM UTC-4, Tom Evans wrote: >>> >>> On Tue, May 21, 2013 at 4:23 PM, Chris Conover <clc...@gmail.com> >>> wrote: >>> > Hello, >>> > >>> > I'm having an issue looking up objects immediately after they are >>> saved and >>> > am wondering if anyone has any advice on how to address the problem. >>> > Specifically, I'm saving an object in a view (nothing fancy, a simple >>> > save()) and then kicking off a Gearman task to do some operations on >>> that >>> > saved object in the background. I pass the newly created object's PK >>> as data >>> > to the Gearman worker which then does a simple >>> Objects.objects.get(pk=PK). >>> > However, almost all of the time this lookup operation fails with an >>> > DoesNotExist exception. I believe the problem has to do with >>> transactions. >>> > Namely, the read in the Gearman worker is happening before the write >>> from >>> > the view is committed to the database. I've tried several things >>> including >>> > refactoring the saving code to be wrapped in a >>> > @transaction.commit_on_success block, moving the worker submission to >>> > post_save and adding a long delay before the Gearman worker does the >>> lookup. >>> > Nothing really seems to solve the problem completely. Even with a 60 >>> second >>> > delay, the lookup fails with some frequency. Am I missing something >>> here? Is >>> > there some Django query cache that I can clear? Or should I just >>> rewrite all >>> > this to just to use a look-back perspective. >>> > >>> > The stack is Django 1.4 connecting to MySQL 5.5.27. Django is handling >>> > 200-1000 requests per second and the database is handling about double >>> that. >>> > >>> > Thanks, >>> > Chris >>> >>> from django import transaction >>> … >>> obj.save() >>> transaction.commit() >>> task.submit(obj.id) >>> >>> You will also need to make sure that gearman is doing things correctly >>> as well. You haven't mentioned what database you are using, but if >>> gearman's DB connection is in a read repeated mode, you can do >>> whatever you like in django but you won't see new data in gearman >>> until gearman's current transaction is committed. >>> >>> Cheers >>> >>> Tom >>> >> -- You received this message because you are subscribed to the Google Groups "Django users" group. To unsubscribe from this group and stop receiving emails from it, send an email to django-users+unsubscr...@googlegroups.com. To post to this group, send email to django-users@googlegroups.com. Visit this group at http://groups.google.com/group/django-users?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
