How about using an autofield? http://docs.djangoproject.com/en/dev/ref/models/fields/#autofield
On Aug 16, 12:25 pm, Alec Shaner <asha...@chumpland.org> wrote: > Regarding your issue with get_next, could be because you're invoking the > method when you define default=get_next(). Try it with just the bare method > name get_next. > > You could also use the aggregate function instead of creating a new model: > > http://docs.djangoproject.com/en/1.2/topics/db/aggregation/#topics-db... > > Just define get_next to call the Max aggregate on your Newspaper model's > number field. > > On Mon, Aug 16, 2010 at 12:39 PM, bagheera <neost...@go2.pl> wrote: > > Hi, i have "number" field in "newspaper" model. I want assign to it > > dynamically a default value, witch would be a incremented by 1 highest value > > so far. > > So i managed to make a little workaround, since i can't query for last > > value of "number" field of model from model itself. > > > I have created new model, witch has only 1 field any 1 record, witch stores > > current highest value. > > I wrote two functions: > > > #-*- coding: utf-8 -*- > > from nml.options.models import Wydanie_opt > > > def set_next(value): > > try: > > option = Wydanie_opt.objects.all()[0] > > if value > option.nr_wydania_next: > > option.nr_wydania_next = value > > option.save() > > except: > > option = Wydanie_opt(nr_wydania_next = value) > > option.save() > > > def get_next(): > > try: > > option = Wydanie_opt.objects.all()[0] > > value = option.nr_wydania_next > > except: > > return 0 > > else: > > return value + 1 > > > Here's code of "newspaper" model: > > > from nml.options.utils import get_next > > > class Wydanie(models.Model): > > nr_wydania = models.PositiveIntegerField(verbose_name = "Numer wydania", > > unique = True, default = get_next(), > > help_text = "Unikalny numer wydania.") > > > The problem is, set_next is working as intended, but get_next() does NOT, > > default value stays the same until i restart dev server. Why? Query isn't > > evaluated? get_next() function isn't called at all? > > Mb there is a better way to implement auto-incrementation. > > Keep in mind that, "nr_wydania" field must be visible and editable, since > > first entered value is unknown, some values may be skipped, and there is no > > order of adding it. > > -- > > Linux user > > > -- > > 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...@googlegroups.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.
