This can work when you know you want to use the object once it's been
retrieved. If all you want to do is check for existence then it's
better to do the check with a:
if Class.objects.filter(pk=pk).count() == 0:
# Do object doesn't exist stuff
else:
# Do object does exist stuff
--
G
On Apr 9, 11:44 pm, johan sommerfeld <johan.sommerf...@gmail.com>
wrote:
> If you don't want to use exception (which I do when doing something
> similar). You can use filter and then check the length of the array
> returned.
>
> def my_view( request , pk ):
> obj = Class.objects.filter( pk = pk)
> if len(obj) != 1:
> return bad_key_view
> obj = obj[0]
> # Do something with obj and return a suitable response.
>
> /J
>
>
>
> On Fri, Apr 9, 2010 at 11:54 PM, Joakim Hove <joakim.h...@gmail.com> wrote:
> > Hello,
>
> > I have something I would presume was a very common pattern. I have a
> > view which gets a primary-key (from the user) as second argument:
>
> > def my_view( request , pk ):
> > obj = Class.objects.get( pk = pk)
> > # Do something with obj and return a suitable response.
>
> > Now, of course I would like to check whether the object identified by
> > 'pk' is in the database, and return a suitable error message if that
> > fails; I was halfway expecting to find a "has_key() / exists() / ..."
> > method, but it seems the only way to handle this gracefully is by
> > catching the DoesNotExist exception?
>
> > I have never really got very friendly with exceptions, I tend to
> > consider them as something exceptional which "should not" happen,
> > whereas the fact that the database does not contain a particular key
> > is in my opinion something quite ordinary and not by any means
> > "exceptional".
>
> > Or maybe I am misunderstanding roally here?
>
> > Joakim
>
> > --
> > You received this message because you are subscribed to the Google Groups
> > "Django users" group.
> > To post to this group, send email to django-us...@googlegroups.com.
> > To unsubscribe from this group, send email to
> > django-users+unsubscr...@googlegroups.com<django-users%2bunsubscr...@google
> > groups.com>
> > .
> > For more options, visit this group at
> >http://groups.google.com/group/django-users?hl=en.
--
You received this message because you are subscribed to the Google Groups
"Django users" group.
To post to this group, send email to django-us...@googlegroups.com.
To unsubscribe from this group, send email to
django-users+unsubscr...@googlegroups.com.
For more options, visit this group at
http://groups.google.com/group/django-users?hl=en.
