I have a model which have a function to calculate the difference between two fields Example: Class MyModel(models.Model): fieldA = models.FloatField() fieldB = models.FloatField() def delta(self): return self.fieldA - self.fieldB Id like to use this model in a GenericView. I can use the function delta as an extraC...
How to find the execution time for various Model API Calls in Django. ...
Hello, i'm building a simple app for Django and I'm facing some problems with my models design, and the use of 'inlines' in the administration interface. The app is to manage projects. A project consists of a name, a description, other fields (e.g. tags...) and of multiple urls (like project url, source code repository url) but the num...
What is the accepted way of checking a model's existence in a Django app? I've seen this method used: def profile_exists(user): try: UserProfile.objects.get(user = user) return True except: return False Is there a built-in function suited for this purpose? ...
I've got two models. One represents a piece of equipment, the other represents a possible attribute the equipment has. Semantically, this might look like: Equipment: tractor, Attributes: wheels, towing Equipment: lawnmower, Attributes: wheels, blades Equipment: hedgetrimmer, Attributes: blades I want to make queries like, wheels = A...
I'm not familiar with django conventions at all so if you do provide advice could you be specific Considering my homepage would contain components of articles: In Zend, in my IndexController I would create models and populate the view with articles and data. What's a convention/structure I could use for the homepage view ( sh...
I'm working on some Django-code that has a model like this: class Status(models.Model): code = models.IntegerField() text = models.CharField(maxlength=255) There are about 10 pre-defined code/text-pairs that are stored in the database. Scattered around the codebase I see code like this: status = Status.objects.get(code=0)...
Hi, I have two files: choices.py class SomeChoice: name = u"lorem" class AnotherChoice: name = u"ipsum" # etc... models.py from django.db import models import choices class SomeModel(models.Model): CHOICES = ( (1, choices.SomeChoice.name), (2, choices.AnotherChoice.name), # etc... ) so...
I can't see any provision for this in the django docs, so how do people go about doing this. My specific case is this. I have a shopping cart, each cart instance has an invoice number field, however the invoice number is only generated if the cart goes to a paid status, so not all shopping cart instances will have an invoice number. I ...
I'm completely confused about why _meta.local_fields returns more fields than the database table contains. The User model inherits from contrib.auth.models.User. $ mysql -u user -p database Enter password: Reading table information for completion of table and column names You can turn off this feature to get a quicker startup wit...
Given the following models implemented in sqlite3 class Parent(models.Model): pass class Children(models.Model): parent=models.ForeignKey(Parent,primary_key=True) After importing data from a spreadsheet into Children I need to get a list of Parents having no children and for this I'm using... Parent.objects.filter(children__...
I see these nice "local flavors" for Canada, but they're only form fields. How would I use them in my model? I can create them all as CharFields sure, but then is there a way to set the default form widget from inside the model so that when I create a ModelForm it'll use them? ...
Firstly, I know how to fix the problem, I'm just trying to understand why it's occuring. The error message: users.profile: Reverse query name for field 'address' clashes with related field 'Address.profile'. Add a related_name a rgument to the definition for 'address'. And the code: class Address(models.Model): country = fie...
I have a model: class Zone(models.Model): name = models.CharField(max_length=128) users = models.ManyToManyField(User, related_name='zones', null=True, blank=True) And I need to contruct a filter along the lines of: u = User.objects.filter(...zones contains a particular zone...) It has to be a filter on User and it has...
Say I have models: class Animal(models.Model): type = models.CharField(max_length=255) class Dog(Animal): def make_sound(self): print "Woof!" class Meta: proxy = True class Cat(Animal): def make_sound(self): print "Meow!" class Meta: proxy = True Let's say I want to do: animals =...
My question is very similar to this question: http://stackoverflow.com/questions/862522/django-populate-user-id-when-saving-a-model Unfortunately I did not quite understand their answer. When a user logs in I want them to be able to submit a link and I have a user_id foreign key that I just can't seem to get to populate. def submit(r...
Hi. I have an inline formset in my admin site. I also have save_as = True in admin.py. My models are, for example: class Poll(models.Model): question = models.CharField(max_length=200, unique = True) pub_date = models.DateTimeField('date published') class Choice(models.Model): poll = models.ForeignKey(Poll) choice = mod...
I want to show the human-readable name for the type selected but I keep getting the stored value. TYPE_CHOICES = ( ('0', 'Basic'), ('1', 'Full'), ('2', 'Intermediate'), ) class ServiceType(models.Model): type = models.IntegerField(max_length=1, choices=TYPE_CHOICES) amount = models.DecimalField(max_digits=10, ...
I have a Django application in which I want to change a field from a ForeignKey to a ManyToManyField. I want to preserve my old data. What is the simplest/best process to follow for this? If it matters, I use sqlite3 as my database back-end. If my summary of the problem isn't clear, here is an example. Say I have two models: class...
Here's an interesting problem, I have a list of users that I list in order of rating, and where two users have the same rating, I have a random number that I use to make sure the list won't always be the same. Currently I do this by executing a query: select app_model1.column1, app_model1.colum2, app_model2.column3 from app_mode...