For anyone coming here wondering if they need an index_together in addition to unique_together to get the index’s performance benefit, the answer for Postgres is no, they are functionally the same.
def remove_duplicated_records(model, fields): “”” Removes records from `model` duplicated on `fields` while leaving the most recent one (biggest `id`). “”” duplicates = model.objects.values(*fields) # override any model specific ordering (for `.annotate()`) duplicates = duplicates.order_by() # group by same values of `fields`; count how many rows are the same duplicates = duplicates.annotate( max_id=models.Max(“id”), count_id=models.Count(“id”) ) # … Read more
Yes you can! Just like your form, you can add help_text to your model fields.
A simple hack I have used is: class SuperFoo(models.Model): name = models.CharField(‘name of SuperFoo instance’, max_length=50) … class Meta: abstract = True class Foo(SuperFoo): … # do something that changes verbose_name of name field of SuperFoo Foo._meta.get_field(‘name’).verbose_name=”Whatever”
I think the above answers are all correct, but I leave mine here as an simple example… class UserProfile(models.Model): import pytz TIMEZONES = tuple(zip(pytz.all_timezones, pytz.all_timezones)) # … timezone = models.CharField(max_length=32, choices=TIMEZONES, default=”UTC”) # …
Your question is very unclear. You should probably go through the django-tutorial. But sure you can insert data into the db from views. Assume you have a model called Foo: models.py class Foo(models.Model): name = models.CharField(max_length=100) view.py from .models import Foo def some_name(request): foo_instance = Foo.objects.create(name=”test”) return render(request, ‘some_name.html.html’)
You need to create an empty migration file and Do your stuff in operations block, as explained in docs. Data Migrations As well as changing the database schema, you can also use migrations to change the data in the database itself, in conjunction with the schema if you want. Now, all you need to do … Read more
The Metaclass approach proposed by thedk is indeed a very powerful way to go, however, I had to combine it with an answer to the question here to have the query return a proxy model instance. The simplified version of the code adapted to the previous example would be: from django.db.models.base import ModelBase class InheritanceMetaclass(ModelBase): … Read more
swappable is an “intentionally undocumented” feature which is currently under development / in-test. It’s used to handle “I have a base abstract model which has some foreign-key relationships.” Slightly more detail is available from Django’s ticketing system and github. Because it’s a “stealth alpha” feature, it’s not guaranteed to work (for anything other than User), … Read more
From the Django documents for Field.default: The default value for the field. This can be a value or a callable object. If callable it will be called every time a new object is created. So do this: from datetime import datetime, timedelta def default_start_time(): now = datetime.now() start = now.replace(hour=22, minute=0, second=0, microsecond=0) return start … Read more