I have a Game Model and a Subscription Model:
class Game(models.Model):
title = models.CharField(max_length=100)
slug = models.SlugField(unique=True)
cover = models.ImageField(upload_to='cover_images')
def __str__(self):
return self.title
class Meta:
ordering = ['title']
class Subscription(models.Model):
user = models.ForeignKey(User, on_delete=models.CASCADE)
game = models.ForeignKey(Game, on_delete=models.CASCADE)
created_at = models.DateTimeField(auto_now_add=True)
updated_at = models.DateTimeField(auto_now=True)
is_active = models.BooleanField(default=True)
def __str__(self):
return str(self.id)
Now I'm trying to figure out how to sort Games by the number of subscribers.
You can do this in Django >= 2.0:
class Game(models.Model):
# Previous code
class Meta:
ordering = [Count('subscription').desc(nulls_last=True)]
In older versions you can do this:
Game.objects.all().annotate(num_subscribers=Count('subscription')
.order_by('-num_subscribers')
Related
I am creating a minimal viable product of a recipe application. I would like to leverage the admin site to create a diary entry that, consists of a recipe, that consists of ingredients with amounts and quantities. I read that inlines are possible. However, I have not successfully been able to implement one.
class Meal(models.Model):
id = models.BigAutoField(primary_key=True, editable=False)
name = models.CharField(max_length=64, unique=True)
class Meta:
verbose_name = ("Meal")
verbose_name_plural = ("Meals")
def __str__(self):
return f"{self.name}"
class Measurement(models.Model):
id = models.BigAutoField(primary_key=True, editable=False)
name = models.CharField(max_length=64, unique=True)
class Meta:
verbose_name = ("Measurement")
verbose_name_plural = ("Measurements")
def __str__(self):
return f"{self.name}"
class Ingredient(models.Model):
id = models.BigAutoField(primary_key=True, editable=False)
name = models.CharField(max_length=64, unique=True)
class Meta:
verbose_name = ("Ingredient")
verbose_name_plural = ("Ingredients")
def __str__(self):
return f"{self.name}"
class Recipe(models.Model):
id = models.BigAutoField(primary_key=True, editable=False)
created_at = models.DateTimeField(auto_now_add=True)
updated_at = models.DateTimeField(auto_now=True)
user = models.ForeignKey(User, on_delete=models.CASCADE)
name = models.CharField(max_length=64)
class Meta:
verbose_name = ("Recipe")
verbose_name_plural = ("Recipes")
def __str__(self):
return f"{self.name}"
class RecipeIngredient(models.Model):
id = models.BigAutoField(primary_key=True, editable=False)
recipe = models.ForeignKey(Recipe, on_delete=models.CASCADE)
quantity = models.CharField(max_length=64, blank=True, null=True)
measurement = models.ForeignKey(Measurement, on_delete=models.CASCADE, blank=True, null=True)
ingredient = models.ForeignKey(Ingredient, on_delete=models.CASCADE)
class Meta:
verbose_name = ("RecipeIngredient")
verbose_name_plural = ("RecipeIngredients")
class Diary(models.Model):
id = models.BigAutoField(primary_key=True, editable=False)
created_at = models.DateTimeField(auto_now_add=True)
updated_at = models.DateTimeField(auto_now=True)
occured_at = models.DateTimeField()
user = models.ForeignKey(User, on_delete=models.CASCADE)
recipe = models.ForeignKey(Recipe, on_delete=models.CASCADE)
class Meta:
verbose_name = ("Diary")
verbose_name_plural = ("Diaries")
According to your requirement, you can use StackedInline or TabularInline. Here is the code for general StackedInline. TabularInline works in the same way.
#admin.py
class Class_1(admin.StackedInline):
model = Model_1
class Class_2(admin.StackedInline):
model = Model_2
class Class_3(admin.ModelAdmin):
inlines = [Class_1,Model_2]
admin.site.register(Model_Name, Class_3)
I am trying to create an educational website using django so I have a class model and a course model. I have tried to use the Many-to-one foreignkey relationship but that doesn't work, I can create classes using foreignkey but that class is not being assigned to that course only. It appears in other courses as well. So how can I make this work? What should I change?
My models.py:
class Class(models.Model):
title = models.CharField(max_length=100)
video = models.FileField(upload_to='class/class_videos',null=True,
validators=[FileExtensionValidator(allowed_extensions=['MOV','avi','mp4','webm','mkv'])])
def __str__(self):
return self.title
class Course(models.Model):
title = models.CharField(max_length=100)
image = models.ImageField(upload_to='class/instructor_pics', null=True)
instructor = models.CharField(max_length=100)
instructor_image = models.ImageField(upload_to='class/instructor_pics', null=True)
students = models.ManyToManyField(User, related_name='courses_joined', blank=True)
classes = models.ForeignKey(Class, on_delete=models.CASCADE, null=True)
slug = models.SlugField(max_length=200, unique=True)
description = models.TextField(max_length=300, null=True)
created = models.DateTimeField(auto_now_add=True)
class Meta:
ordering = ['-created']
def __str__(self):
return self.title
You are using the foreign key in the wrong model. If each class can only have one course, but a single course, can have multiple classes, you should place the ForeignKey in the class model instead of the course model. Your code would be like this:
class Course(models.Model):
title = models.CharField(max_length=100)
image = models.ImageField(upload_to='class/instructor_pics', null=True)
instructor = models.CharField(max_length=100)
instructor_image = models.ImageField(upload_to='class/instructor_pics', null=True)
students = models.ManyToManyField(User, related_name='courses_joined', blank=True)
slug = models.SlugField(max_length=200, unique=True)
description = models.TextField(max_length=300, null=True)
created = models.DateTimeField(auto_now_add=True)
class Meta:
ordering = ['-created']
def __str__(self):
return self.title
class Class(models.Model):
title = models.CharField(max_length=100)
video = models.FileField(upload_to='class/class_videos',null=True,
validators=[FileExtensionValidator(allowed_extensions=['MOV','avi','mp4','webm','mkv'])])
course = models.ForeignKey(Course, on_delete=models.CASCADE, null=True, related_name='classes')
def __str__(self):
return self.title
And when you want to list the classes of a single course, you can use this code (you should use the related_name field in the source model like the way I have used in the class model):
course = Course.objects.filter(some_filter=some_value).first()
course.classes.first() # This will return the first class of the course
I have start fresh with Django.
I am creating a blog and I need a hint now.
I want to add tags to my posts.
So I created a model for my tags:
class Tag(models.Model):
name = models.CharField(max_length=200, unique=True)
def __str__(self):
return self.name
This is my Post Model
class Post(models.Model):
title = models.CharField(max_length=200, unique=True)
slug = models.SlugField(max_length=200, unique=True)
author = models.ForeignKey(User, on_delete= models.CASCADE,related_name='blog_posts')
updated_on = models.DateTimeField(auto_now= True)
content = models.TextField()
created_on = models.DateTimeField(auto_now_add=True)
status = models.IntegerField(choices=STATUS, default=0)
class Meta:
ordering = ['-created_on']
def __str__(self):
return self.title
What is the best way, that the user can select in the admin area tags for the post and more than one or create a new tag?
In the Post class， add a field ManyToMany
class Post(models.Model):
title = models.CharField(max_length=200, unique=True)
slug = models.SlugField(max_length=200, unique=True)
author = models.ForeignKey(User, on_delete= models.CASCADE,related_name='blog_posts')
updated_on = models.DateTimeField(auto_now= True)
content = models.TextField()
created_on = models.DateTimeField(auto_now_add=True)
status = models.IntegerField(choices=STATUS, default=0)
tag = models.ManyToManyField(Tag)
class Meta:
ordering = ['-created_on']
def __str__(self):
return self.title
You are looking for InlineModelAdmin particulary section regarding
Working with many-to-many models
something as following:
class TagInline(admin.TabularInline):
model = Post.tags.through
class PostAdmin(admin.ModelAdmin):
inlines = [
TagInline,
]
Also you are missing relationship on your model which should be ManyToMany
class Post(models.Model):
...
tags = models.ManyToManyField(Tag)
Its my first time trying django as my first programming project.
I have a hierarchy structure of Company -> Business -> Outlets using foreign key.
I would like to know is there anyway to structured it in a way where the Company status is saved as inactive status, the remaining business, outlets models that will be triggered as inactive status.
from django.db import models
from django.contrib.auth.models import User
# Create your models here.
class Common_Info(models.Model):
"""(Common description)"""
name = models.CharField(blank=True, max_length=100)
slug = models.SlugField(unique=True, max_length=120)
address_1 = models.CharField(max_length=50, null=True)
address_2 = models.CharField(max_length=50, null=True)
address_3 = models.CharField(max_length=50, null=True)
post_code = models.CharField(max_length=6, null=False)
registration_no. = models.CharField(max_length=15,null=False)
gst_no. = models.CharField(max_length=15,null=True)
telphone_no. = models.CharField(max_legth=15, null=False)
fax_no. = models.CharField(max_legth=15, null=True)
email_address = models.EmailField(max_length=254,null=False)
"""(Status choice)"""
Active_Status = 1
Inactive_Status = 0
STATUS_CHOICES = (
(Active_Status, 'Active'),
(Inactive_Status, 'Inactive'),
)
status = models.IntegerField(choices=STATUS_CHOICES, default=Active_Status)
create_date = models.DateTimeField(auto_now_add=True)
create_user = models.ForeignKey(settings.AUTH_USER_MODEL)
modified_date = models.DateTimeField(auto_now_add=True)
modified_user = models.ForeignKey(settings.AUTH_USER_MODEL)
class Meta:
abstract = True
class Company(Common_Info):
"""(Company additional description)"""
gst_no. = models.CharField(max_length=15,null=True)
class Meta:
verbose_name ='Company'
verbose_name_plural = "Companies"
def __unicode__(self):
return u"Company"
class Business(Common_Info):
"""(Business description)"""
parent=models.ForeignKey(Company, on_delete=models.CASCADE)
gst_no. = models.CharField(max_length=15,null=True)
class Meta:
verbose_name ='Business'
verbose_name_plural = "Businesses"
def __unicode__(self):
return u"Business"
class Outlet(Common_Info):
outlet_code = models.CharField(max_length=3, unique=True)
business_name = models.ForeignKey(Business, on_delete=models.CASCADE)
def __unicode__(self):
return u"Outlet"
Is there something similar to cascade on delete or other more elegant way of extending such a function across other apps in the project.
I don't think there is any direct support in ORM. But you can override the save() method to update the related the outlets and business. You can use related objects to fetch business and outlets. Here is an example:
class Company(Common_Info):
"""(Company additional description)"""
gst_no. = models.CharField(max_length=15,null=True)
class Meta:
verbose_name ='Company'
verbose_name_plural = "Companies"
def __unicode__(self):
return u"Company"
def save(self, *args, **kwargs):
super(Company, self).save(*args, **kwargs)
if self.status == 0:
self.business_set.update(status=self.status)
self.outlet_set.update(status=self.status)
I am a django newbie and have one more big struggle for longer time... :/
User can choose a 'main language' which is set as ForeignKey. User can choose 'further languages' as ManyToMany (Checkbox). Assuming, user selects english as 'main' language, so english has to be filterd out from the 'further languages'... have been searching so much and have no idea how to do it. Is this even possible without JavaScript?
Of course, I could set the 'queryset' in the second form but it would filter the objects after the submit... The similar problem is, when a selected country has to be connected to the proper zipcodes...
I am very thankful for any hints.
Best regards.
class Country(models.Model):
enter code here
country = models.CharField(max_length=40)
active = models.BooleanField(default=True)
class Meta:
verbose_name_plural = 'Länder'
def __str__(self):
return self.country
class ZipCode(models.Model):
zipcode = models.CharField(max_length=5)
city = models.CharField(max_length=255)
active = models.BooleanField(default=False)
class Meta:
verbose_name_plural = 'Postleitzahlen'
def __str__(self):
return '{0} {1}'.format(self.zipcode, self.city)
class MainLanguage(models.Model):
language = models.CharField(verbose_name='Hauptsprache', max_length=40)
active = models.BooleanField(default=True)
class Meta:
verbose_name_plural = 'Hauptsprachen'
ordering = ['language']
def __str__(self):
return self.language
class SecondLanguage(models.Model):
language = models.CharField(verbose_name='weitere Sprachen', max_length=40)
active = models.BooleanField(default=False)
class Meta:
verbose_name_plural = 'weitere Sprachen'
ordering = ['language']
def __str__(self):
return self.language
class CustomUserprofile(models.Model):
user = models.OneToOneField(User)
name = models.CharField(verbose_name='Vorname', max_length=40,
null=True, blank=True)
country = models.ForeignKey(Country, verbose_name='Land',
null=True, blank=True)
zipcode = models.ForeignKey(ZipCode, blank=True, null=True)
main_language = models.ForeignKey(
MainLanguage, verbose_name='Hauptsprache',
null=True, blank=True)
second_language = models.ManyToManyField(
SecondLanguage, verbose_name='weitere Sprachen',
null=True, blank=True)
class UserProfileForm(forms.ModelForm):
second_language = forms.ModelMultipleChoiceField(
queryset=SecondLanguage.objects.all(),
required=False,
widget=forms.CheckboxSelectMultiple)
class Meta:
model = CustomUserprofile
exclude = ('user',)