Changed the variable names to make it a little more readable. Method now returns "amount" (formerly "total"):
Class Item(models.Model): name = models.CharField(max_length=100) price = models.DecimalField(max_digits=9, decimal_places=2) quantity = models.IntegerField(default=1) total_cost = models.DecimalField(max_digits=12, decimal_places=2, blank=True, null=True, editable=False) def calc_total(self): amount = (self.price * self.quantity) return amount def save(self): self.total_cost = self.calc_total() super(Item, self).save() Now I get a different error when I try to save an Item: OperationalError at /admin/spending/item/add/ (1054, "Unknown column 'total_cost' in 'field list'") On Aug 25, 3:45 pm, nicksergeant <[EMAIL PROTECTED]> wrote: > Should 'total_cost' simply: > > return total > > instead of: > > return total_cost(total) > > On Aug 25, 5:22 pm, Chris Amico <[EMAIL PROTECTED]> wrote: > > > This seems like it should be simple, but I'm getting errors. > > > I have a model tracking individual purchases. User inputs an item cost > > and quantity; I want the total cost calculated. Here are the relevant > > parts: > > > class Item(models.Model): > > name = models.CharField(max_length=100) > > price = models.DecimalField(max_digits=9, decimal_places=2) > > quantity = models.IntegerField(default=1) > > total_cost = models.DecimalField(max_digits=12, > > decimal_places=2, > > blank=True, > > null=True, > > editable=False) > > > def total_cost(self): > > total = (self.price * self.quantity) > > return total_cost(total) > > > def save(self): > > self.total_cost = self.total_cost() > > super(Item, self).save() > > > The error I get is: > > > NameError at /admin/spending/item/add/ > > global name 'total_cost' is not defined > > > Not sure what that means. Thoughts? Am I missing an exceedingly > > obvious way to do this? --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/django-users?hl=en -~----------~----~----~----~------~----~------~--~---