django-orm

问题 I am stuck in django's group module can any one tell me how to solve it. my problem is now i'm dispalying the username of the logged-in user, i want to display group-name and the profiles present in that group along with the username.and my views are like this, def user(request): context = {'user': request.user} return render_to_response('username.html', context, context_instance=RequestContext(request)) now what do I need to add in order to achieve my requirement forms.py class LoginForm

问题 I have a class Assembly class Assembly(models.Model): room = models.ForeignKey("Room", related_name="assemblies") name = models.CharField(max_length=200) number = models.IntegerField() position = models.CharField(max_length=200, blank=True) components = models.ManyToManyField("material.Component", through="m2m_Assembly_Components") connections = models.ManyToManyField("Assembly", through="Connection") category = models.ForeignKey("Category", default=0) notes = models.TextField(blank=True)

问题 I am using Django 2.2 along with MySQL. I have the following query: Here's the model for the reference : class TrackCount(models.Model): people_count_obj_id = models.CharField(primary_key=True, default=uuid.uuid4, editable=False, max_length=255) recorded_at = models.DateTimeField() camera = models.ForeignKey(Camera, on_delete=models.PROTECT) store = models.ForeignKey(Store, on_delete=models.PROTECT) people_count_in = models.IntegerField() people_count_out = models.IntegerField() created_at =

问题 I am using Django 2.2 along with MySQL. I have the following query: Here's the model for the reference : class TrackCount(models.Model): people_count_obj_id = models.CharField(primary_key=True, default=uuid.uuid4, editable=False, max_length=255) recorded_at = models.DateTimeField() camera = models.ForeignKey(Camera, on_delete=models.PROTECT) store = models.ForeignKey(Store, on_delete=models.PROTECT) people_count_in = models.IntegerField() people_count_out = models.IntegerField() created_at =

问题 In Django, what is the most efficient way to create a nested dictionary of data from querying related and child models? For example, if I have the following models: Parent Children Pets I've seen django's model_to_dict method, and that's pretty cool, so I imagine I could loop through each level's queryset and create a bunch of DB calls on each level, for each instance, but is there a better way? For example, could "prefetch_related" be used to get all three tiers as it is used to get two

问题 I have an IntegerField declared as below on a model: amount = models.IntegerField() When accessing it, it sometimes returns a string. The proximate cause for this is that it has had a string assigned to it. So far, so unmysterious. It also returns a string even after it has been saved. This strikes me as a little surprising: it would be nice if IntegerField coerced its value to an integer on assignment (or, at the latest, on save), so the user could rely on it being an integer. (My

问题 I have an IntegerField declared as below on a model: amount = models.IntegerField() When accessing it, it sometimes returns a string. The proximate cause for this is that it has had a string assigned to it. So far, so unmysterious. It also returns a string even after it has been saved. This strikes me as a little surprising: it would be nice if IntegerField coerced its value to an integer on assignment (or, at the latest, on save), so the user could rely on it being an integer. (My

问题 I am attempting to perform an order_by based a m2m field, but it ends up creating duplicate entries in my queryset. I have been searching through the django documentation and related questions on stack exchange, but I haven't been able to come up with any solutions. Models: class WorkOrder(models.Model): ... appointment = models.ManyToManyField(Appointment, null=True, blank=True, related_name = 'appointment_from_schedule') ... class Appointment(models.Model): title = models.CharField(max

问题 I'm looking to do a complex filter using Django's ORM. Models: class Book(models.Model): title = models.TextField() bestseller = models.BooleanField(default=False) class Author(models.Model): name = models.TextField() books = models.ManytoManyField(Book) How would I query for all authors who have at least one best-selling book? Query: best_authors = Author.objects.filter(<relevant filter>) Edit: According to the documentation, the following should work: best_authors = Author.objects.filter

问题 I have the following model: class Campaign(models.Model): some_campaign_field = models.CharField() class Position(models.Model): campaign = models.ForeignKey(Campaign) some_position_field = models.CharField() class Trade(models.Model): position = models.ForeignKey(Position) some_trade_field = models.CharField() In other words, I have Campaigns which can have multiple Positions. In turn each position within the campaign can have multiple Trades. Is there an efficient way (ie: minimal database