django-models

问题 I have a parent class which is being extended by 3 different models. The parent class has a field called foo lets say, and this field needs to be always null for one of the sub-classes. How can I ensure this? Right now, I am using null=True , and editable=False constraints. However, these can be circumvented from the shell or an API if the field is exposed during object creation. class ThirdSubclass(ParentClass): # Over-ridden field from abstract parent class foo = models

问题 I have a model with an integer field and would like to have an alternative form input render other than the default textbox, so that I have the following: models.py: myfield = models.IntegerField(default=7, blank=True) Would like to have the following: [x] Choice A (value 0) [ ] Choice B (value 1) [x] Choice C (value 2) So that upon save the choices would be calculated like the the following: (since choice A and C are selected and 2 is not selected). myfield = sum(choice selected multiplied

问题 I'm porting an existing database application over to Django (so much better!), and have created Django models as follows: class Book(models.Model): title = models.CharField(max_length=200) author = models.ForeignKey(Author) subject = models.ManyToManyField(Subject, related_name='subject') class Author(models.Model): name = models.CharField(max_length=200) class Subject(models.Model): name = models.CharField(max_length=200) I've populated the models from existing data. The problem is that the

问题 I'm porting an existing database application over to Django (so much better!), and have created Django models as follows: class Book(models.Model): title = models.CharField(max_length=200) author = models.ForeignKey(Author) subject = models.ManyToManyField(Subject, related_name='subject') class Author(models.Model): name = models.CharField(max_length=200) class Subject(models.Model): name = models.CharField(max_length=200) I've populated the models from existing data. The problem is that the

问题 I want to restrict the views for each user i.e a user can view only those account details that are related to him only. For this i have created a Filter where i want to pass the Logged in User details. Below is the snapshot of filter.py class networkFilterUserbased(django_filters.FilterSet): def __init__(self, *args, **kwargs): super().__init__(*args,**kwargs) request = kwargs['request'] username = request.user.id my_choices = NetworkRelatedInformation.objects.values_list('account', 'account_

问题 I'm looking for a generic way in Python to instantiate class by its name in similar way how it is done in Java without having to explicitly specify the class name in IF..ELIF condition. This is because I have several different models and serializers and want to make them addressable by parameters in the HTTP request. It is to enhance loose coupling and modularity. For example https://www.domain.com/myapp/sampledata.json?model=<modelname> should get the classes <modelname> and <modelname

问题 I'm coding a news website.News model has a ManyToManyField foreign key named tag . Here is my News model: class News(models.Model): title = models.CharField(max_length=100, verbose_name='title') category = models.ForeignKey(Category, on_delete=models.CASCADE, related_name="cate", blank=True, verbose_name='Category') tag = models.ManyToManyField(Tag, blank=True, verbose_name='Tags') class Meta: verbose_name = "新闻" verbose_name_plural = verbose_name def __str__(self): return self.title Here is

问题 I am trying to edit the fields of one of my objects in the Django admin site, I also have a Cloudinary image field in my model. The issue is, anytime I try to make an edit to one of the CharField s of my object, I get the error: value too long for type character varying(100) which I later found out that every time I finish my edits and I am trying to save, it looks for a new image to replace the current image of my imagefile even though I did not touch my imagefile , thus it returns an empty

问题 Hello i'm using dates for search queries. But i am getting runtime error. RuntimeWarning: DateTimeField Jobs.job_created_on received a naive datetime (2019-01-17 00:00:00) while time zone support is active. Views.py class JobListView(LoginRequiredMixin, generic.TemplateView): template_name = 'admin/jobs/job.html' def get(self, request, *args, **kwargs): context = super(JobListView, self).get_context_data(**kwargs) if 'status' in request.GET: form = JobSearchForm(request.GET) if form.is_valid(

问题 I would like to allow people that don't have access to the Django project root folder (so no access to settings.py file and no DB password) to use specific models outside of Django. I would like some users to be able to query certain tables in the database using the powerful Django structure (querysets etc...) without giving full access to all the tables. Would any of the following strategies work? Is it even possible to do that? And what are the best practices for this kind of issues? Idea 1