[FIXED] How to use prefetch_related with Django's DetailView

Issue

I want to use prefetch_related with Django's DetailView.

Model:

class Customer(models.Model):
    name = models.CharField(
        verbose_name='customer name',
        max_length=100
    )
    # Other fields

class Packet(models.Model):
    customer = models.ForeignKey(
        Customer
    )
    # Other fields

class Credit(models.Model)   :
    customer = models.ForeignKey(
        Customer
    )
    # Other fields

View:

class CustomerDetailsView(LoginRequiredMixin, DetailView):
    model = Customer
    http_method_names = ['get']
    template_name = 'detail_templates/customer_details.html'

Templates:

{% for p in object.packet_set %}
    {{ do something }}
{% endif %}

{% for p in object.credit_set %}
    {{ do something }}
{% endif %}

Tried:

class CustomerDetailsView(LoginRequiredMixin, DetailView):
    model = Customer
    http_method_names = ['get']
    template_name = 'detail_templates/customer_details.html'

    def get_queryset(self):
        queryset = super(CustomerDetailsView, self).get_queryset()
        pk = self.kwargs.get(self.pk_url_kwarg, None)
        return queryset.filter(id=pk).prefetch_related('packet_set', 'credit_set')

debug_toolbar shows no improvement. How do I prefetch_related packet and credit

Solution

There is no sense to use prefetch_related() in the DetailView. This view loads the single master object with get() while prefetch_related() is usable for loading related objects of multiple master objects.

Answered By - catavaran