在Django中按外键过滤

Question

We extended Django's User Model with our CompanyRecord model. Every CompanyRecord is a User which all have a profile. When that user logins to system, we can pull it's data in it's CompanyRecord.

Our Campaign model is related to our CompanyRecord by a foreign key. Thus every CompanyRecord has a number of campaigns. I want to take those Campaigns which are related to the CompanyRecord. Basically, a CompanyRecord is a User. A CompanyRecord has many Campaigns. When a User which is also a CompanyRecord logins to system, I want to get it's associated Campaigns.
In view, I want to take all the campaigns and filter them as, only the Campaigns which are related to our User would show up.

Necessary parts of our data model

    #models.py
    class CompanyRecord(models.Model):
        user = models.OneToOneField(User)
        company_id = models.IntegerField(primary_key=True)
        company_name = models.CharField(max_length=100)



    class Campaign(models.Model):
        campaign_id = models.IntegerField(primary_key=True)
        company_id = models.ForeignKey(CompanyRecord)
        category_id = models.ManyToManyField(Category)
        campaign_title = models.CharField(max_length=100)


And the part of view.py

    @login_required
    def kampanyalar(request):
        if not request.user.is_authenticated():
            return HttpResponseRedirect('/login/')
        company = request.user.get_profile
        userscampaign = Campaign.objects.filter( ###problem### )
        content = {'kampanyalar': kampanyalar, 'sirket':sirket}
        return render_to_response('kampanyalar.html', content, context_instance=RequestContext(request))

Answer 1

Get all the Campaign s for a CompanyRecord by reversing the relationship and using company.campaign_set :

company = request.user.get_profile()
userscampaign = company.campaign_set.all()

See also:

• Following relationships “backward”
• Django reverse lookup of foreign keys