django-managers

问题 In my work we want to run a server with multiple databases. The databases switching should occur when you acces a url like http://myapp.webpage.com or http://other.webpage.com . We want to run only one server instance and at the moment of the HTTP request switch the database and return the corresponding response. We've been looking for a mantainable and 'Django-friendly' solution. In our investigation we have found possible ways to do this, but we have not enough information about. Option 1:

问题 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() forum.topic_count = topic.objects.filter(forum = forum).count() Here's my view : def test(request, post_id): post = topic.objects.get(id = int(topic_id)

问题 I want to overwrite the custom objects model manager to only return objects a specific user created. Admin users should still return all objects using the objects model manager. Now I have found an approach that could work. They propose to create your own middleware looking like this: #### myproject/middleware/threadlocals.py try: from threading import local except ImportError: # Python 2.3 compatibility from django.utils._threading_local import local _thread_locals = local() def get_current

问题 I have a function in a Manager which activates a user account via a key. When a key is provided, several checks need to be performed: does the key exist? has the key expired? and then if not, the manager activates the account. def activate(key): try: profile = self.get(key=key) except self.model.DoesNotExist: return None if not profile.key_expired(): ## Activate user return user return None The issue is of course, that this returns False for both 'the key doesn't exist', and 'the key given is

问题 I am trying to develop a Django application that has built-in logic around temporal states for objects. The desire is to be able to have a singular object representing a resource, while having attributes of that resource be able to change over time. For example, a desired use case is to query the owner of a resource at any given time (last year, yesterday, tomorrow, next year, ...). Here is what I am working with... class Resource(models.Model): id = models.AutoField(primary_key=True) class

问题 I am trying to get my head around writing Custom managers. I found the online documentation a little sparse. Toying around myself with code, I discovered the following patterns: Given the following model... class QuestionQuerySet(models.QuerySet): def QS_first (self): return self.first() class QuestionManager(models.Manager): def get_queryset(self): return QuestionQuerySet(self.model, using=self._db) def MN_first(self): return self.get_queryset().first() class Question(models.Model): front =

问题 I would like to add a custom manager which can be called from a template, but does not affect the entire model (e.g. admin views) and which listens to a parameter set in the request (user_profile). The following is what I have so far: models.py: class CurrentQuerySet(models.query.QuerySet): def current(self): return self.filter(id=1) ## this simplified filter test works.. class CurrentManager(models.Manager): use_for_related_fields = True def get_query_set(self): return CurrentQuerySet(self

问题 Not really sure what the difference is. Seems like all the Manager does is have a bunch of functions related to the Model. But these functions could also be placed in the Model too.... Django documentation describes the Manager as follows, A Manager is the interface through which database query operations are provided to Django models. So is there anything else fundamentally different about the Manager than this simple abstraction? Or a better question: what methods should be defined in the

问题 I used to think QuerySet method return QuerySet instances, but it apparently not. For instance, count() is a queryset method not manager's How do I decide which functions go to custom QuerySet and which go to custom Manager class? 回答1: It makes sense to be able to access some functions like count() on the manager and the queryset. This allows you to do: Blog.objects.count() # total number of blogs Blog.objects.filter(status='PUBLISHED').count() # Number of published blogs Django has a method

问题 I have several models connected to each other with ForeignKeys relationships. The main one in this sort of hierarchy contains a owner field. I would like to create a single custom manager for all these models that changes the returned queryset depending on the models that is calling it. I know that manager can access self.model to get the model that it is attached to. Class Main(models.Model) owner=models.ForeignKey (User) owned = OwnedManager() Class Second(models.Model) main=models