Question

I have another problem. How to fix it? I am a beginner in Django.

My error:

AttributeError at /magazines/
‘Magazine’ object has no attribute ‘items_set’

class Item(models.Model):
    name = models.CharField(max_length=50)
    item_price = models.DecimalField(max_digits=5, decimal_places=2)

class Magazine(models.Model):
    items = models.ManyToManyField('Item', blank=True, null=True)
    owner = models.ForeignKey(User, related_name='u_item')  

def show(request): #magazines items and total price of all items in this magazine
        user = request.user
        magazines = Magazine.objects.filter(owner=user)

        for m in Magazine.objects.filter(owner=user):
            total = m.items_set.all().annotate(total=Sum('item_price'))
            print 'Total cost for items in {0} is {1}'.format(m,total)


        return render_to_response('magazines.html', {'magazines': magazines, 'total': total})

Answer 1

Just try:

total = m.items.all().annotate(total=Sum('item_price'))