django-models

问题 Can someone please explain why is meta class used in the following example. Ex: Class Employee (models.Model): name = models.ForeignKey(name) Gender = models.IntegerField() class Meta: ordering = ["Gender"] Thanks. 回答1: Because author/programmer wants to sort results by value of Gender field. 回答2: Django models use the Meta class to contain extra information about the model that would not necessarily be appropriate to contain within the model class itself. Note that this is not the same as

问题 I have json file in my static folder in my django project. And I want to save the data from json file to my Django Database. This is my model.py from django.db import models class Coming_Soon(models.Model): movie_id = models.CharField(primary_key=True, max_length=11) movie_title = models.TextField(blank=True, max_length=100) image_url = models.TextField(blank=True) synopsis = models.TextField(blank=True) rating = models.TextField(default="MTRCB rating not yet available") cast = models

问题 I'm trying to make dynamic upload path to FileField model. So when user uploads a file, Django stores it to my computer /media/(username)/(path_to_a_file)/(filename). E.g. /media/Michael/Homeworks/Math/Week_1/questions.pdf or /media/Ernie/Fishing/Atlantic_ocean/Good_fishing_spots.txt VIEWS @login_required def add_file(request, **kwargs): if request.method == 'POST': form = AddFile(request.POST, request.FILES) if form.is_valid(): post = form.save(commit=False) post.author = request.user post

问题 I am making a small web application that allow user to perform OCR on the selected image and provides the JSON output in a tabular Format like this. JSON DATA : { "data": { "test_1": { "test_name": "FASTING SUGAR", "results": "121.00", "units": "mg%", "low_range": 70.0, "high_range": 110.0 } } } What I'm facing now is when I'm selected new image to add values in the table, it overrides the values instead of appending. And what I want is to append new value in the table by choosing another

问题 Hi have this structure to handle users posts and comments my post model is from django.db import models from django.contrib.auth.models import User class Post(models.Model): user = models.ForeignKey(User, on_delete=models.CASCADE, default=0) profile = models.ForeignKey('users.Profiles', on_delete=models.CASCADE, null=True, default=1, blank=True) title = models.CharField(max_length=100, blank=True, null=True) desc = models.CharField(max_length=1000, blank=True, null=True) photo = models

问题 One of my view in Django executes save operations on 6-7 tables. I want these transactions to be atomic I,e if the 5th or 6th transaction fail I want to rollback all the previous saves. The view contains a try-except block to handle the exceptions raised. It looks something like this: @transaction.atomic def my_view(request): sid = transaction.savepoint() try: Table1.save() Table2.save() Table3.save() Table4.save() Table5.save() Table6.save() Table7.save() # This might fail. In case of

问题 models.py class Event(models.Model): name = models.CharField(max_length=20, unique=True) distance = models.IntegerField() date = models.DateField() class Category(models.Model): name = models.CharField(max_length=20, unique=True) description = models.CharField(max_length=20, unique=True) isnew = models.BooleanField(default=False) class Result(models.Model): event = models.ForeignKey(Event) category = models.ForeignKey(Category) score = models.IntegerField() I want to do a query to return a

问题 models.py class Event(models.Model): name = models.CharField(max_length=20, unique=True) distance = models.IntegerField() date = models.DateField() class Category(models.Model): name = models.CharField(max_length=20, unique=True) description = models.CharField(max_length=20, unique=True) isnew = models.BooleanField(default=False) class Result(models.Model): event = models.ForeignKey(Event) category = models.ForeignKey(Category) score = models.IntegerField() I want to do a query to return a

问题 For a project in Django I have to use two databases: default and remote . I have created routers.py and everything works fine. There was a requirement to create a table on the remote database and I created migration, run it and the table django_migrations was created. I want to have only one table django_migrations , in the default database. The relevant part of routers.py is here: class MyRouter(object): # ... def allow_migrate(self, db, app_label, model_name=None, **hints): if app_label ==

问题 Say I have the following models that have a many-to-many relationship: models.py: class Foo(models.Model): name = models.TextField() class Bar(models.Model): name = models.TextField() foos = models.ManyToManyField(Foo, related_name='bars') And then having defined them in admin in the following way: admin.py @admin.register(Foo) class FooAdmin(admin.ModelAdmin): """Foo admin.""" list_display = ('name',) search_fields = ('name',) @admin.register(Bar) class BarAdmin(admin.ModelAdmin): """Bar