On Mon, Oct 13, 2008 at 5:27 AM, xkill <[EMAIL PROTECTED]> wrote: > > Hello, > > I try to update a m2m relation. > > So this is the problem: > > models.py > --------------- > from django.db import models > > class instruments(models.Model): > name = models.CharField(max_length=10) > > class people(User): > objects = UserManager() > phone = models.CharField(max_length=9, blank=True, null=True) > movil = models.CharField(max_length=9, blank=True, null=True) > > class relations(models.Model): > person = models.ForeignKey(people) > instrument = models.ForeignKey(instruments) > def __unicode__(self): > return '%s => %s' % (self.person, self.instrument > > class concerts(models.Model): > title = models.CharField(max_length=80) > date = models.DateTimeField() > description = models.TextField() > musicians = models.ManyToManyField(relations, blank=True, > null=True) > def __unicode__(self): > return self.title > > > If I add some concerts with musicians, and I need to change the > relation of the person with the instrument. > I think updating the relations class using the id to update the > instrument. > > How can I get the IDs of the relations associated to the m2m > (musicians) field? > > If I use: >>>> from my_project.test.models import concerts, relations, people, instruments >>>> b = concerts.objects.get(id = 2) >>>> b.title > u'Test2 Concert' >>>> b.musicians.all() > [<relations: xkill => Djembe>, <relations: felipe => Tambourin>, > <relations: Juan => Djembe>] > > > But I want to change the relation 'Juan => Djembe' to 'Juan => > Tambourin'. How can I do it?
The model that you are using for the m2m relation is just another model, so if you want to modify an instance of that model, select an instance it and change it directly. >>> p = person.objects.get(name='Juan') >>> r = relation.objects.get(person__name='Juan', instrument__name='Djembe') >>> tamb = instrument.objects.get(name='Tambourin') >>> r.instrument = tamb >>> r.save() Also - as a matter of style, it's a good habit to get into the capitalization scheme suggested by PEP8 [1] - that means that class/model names should be captialized (i.e., class Person, not class person) [1] http://www.python.org/dev/peps/pep-0008/ Yours, Russ Magee %-) --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/django-users?hl=en -~----------~----~----~----~------~----~------~--~---
