join when it is not needed

Can anyone me explain why django here uses join. Let say I have: class List(models.Model): property = models.ForeignKey(Property, related_name="List") class Property(models.Model): name = models.CharField(...) property = Property.objects.get(pk=100) list = List.objects.get(property=prop

Model design solution

I am creating shop, but need advise on model/db design on product part: class Product(models.Model): name = models.CharField(max_length=250) typeid = models.IntegerField() pdata = models.IntegerField() price = ... visible = ... typeid and pdata is for extending product inform