Always Defer a Field in Django Question: How do I make a field on a Django model deferred for all queries of that model without needing to put a defer on every query? Research This was requested as a feature in 2014 and rejected in 2022. Baring such a feature native to Django, the obvious …
Django: Create a superuser in a data migration Question: Goal: automatically creating a superuser I’m trying to create a default user, specifically a superuser, in an early data migration, so whenever my Django application is run in my Docker container, it already has a superuser with which I can access the admin site. I had …
How to write manager class which use filter field as computed field not as a part of model fields? Question: I have a model Student with manager StudentManager as given below. As property gives the last date by adding college_duration in join_date. But when I execute this property computation is working well, but for StudentManager …
When should I use a custom Manager versus a custom QuerySet in Django? Question: In Django, custom managers are a great way to organize reusable query logic. The Django documentation on Custom managers says: There are two reasons you might want to customize a Manager: to add extra Manager methods, and/or to modify the initial …
Django ORM – objects.filter() vs. objects.all().filter() – which one is preferred? Question: Very often I see constructs like MyModel.objects.all().filter(…) which will return a QuerySet of the default Mananger. At first all() seems to be quite redundant, because MyMode.objects.filter(…) delivers the same result. However, this seems to be safe for the default Manager only, because of …
AttributeError: 'Manager' object has no attribute 'get_by_natural_key' error in Django? Question: I am using Django ‘1.5c1’. I have this line in my settings.py: AUTH_USER_MODEL = ‘fileupload.galaxyuser’ Here’s my Galaxyuser model: class GalaxyUser(models.Model): id = models.IntegerField(primary_key=True) create_time = models.DateTimeField(null=True, blank=True) update_time = models.DateTimeField(null=True, blank=True) email = models.CharField(max_length=765) password = models.CharField(max_length=120) external = models.IntegerField(null=True, blank=True) deleted = …
Manager isn't accessible via model instances Question: I’m trying to get model objects instance in another one and I raise this error : Manager isn’t accessible via topic instance Here’s my model : class forum(models.Model): # Some attributs class topic(models.Model): # Some attributs class post(models.Model): # Some attributs def delete(self): forum = self.topic.forum super(post, self).delete() …
Django Manager Chaining Question: I was wondering if it was possible (and, if so, how) to chain together multiple managers to produce a query set that is affected by both of the individual managers. I’ll explain the specific example that I’m working on: I have multiple abstract model classes that I use to provide small, …
