问如何将外键值分配给我的帖子

EN

def post(self, request, *args, **kwargs):
    form = BusinessDetailForm(request.POST,request.FILES or None) 
    form2 = MultipleImageForm(request.POST or None, request.FILES or None)
    files = request.FILES.getlist('images')
    if all([form.is_valid(),form2.is_valid()]):
        forms = form.save(commit=False) 
        geolocator = Nominatim()
        location = geolocator.geocode(self.request.POST.get("pin_code",False))
        forms.latitude = location.latitude
        forms.longitude = location.longitude 
        forms.created_by = self.request.user 
        forms.themes = self 
        # forms.object_id = int(self.request.POST.get("id",False))
        forms.save()

class BusinessDetail(models.Model):
    # content_type = models.ForeignKey(ContentType,on_delete = models.CASCADE)
    # object_id = models.PositiveIntegerField()
    # content_object = GenericForeignKey('content_type','object_id')
    themes = models.ForeignKey(Themes,on_delete=models.CASCADE,primary_key=False)

    # object_id = models.PositiveIntegerField()

    created_by =models.ForeignKey(settings.AUTH_USER_MODEL,on_delete=models.CASCADE,primary_key=False)
    listin_catagory =models.CharField(max_length=200,choices=listin_Catagory,blank=True)
    business_name =models.CharField(max_length=200,blank=True)

    #themes table
class Themes(models.Model):
    theme_created_by =models.ForeignKey(settings.AUTH_USER_MODEL,on_delete=models.CASCADE,primary_key=False)
    default_theme = models.BooleanField(blank=True,default=False)
    technology_theme = models.BooleanField(blank=True,default=False)