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DJANGO get objects in sql like join

Context: I'm forcing my self to learn django, I already wrote a small php based website, so I'm basically porting over the pages and functions to learn how django works.
I have 2 models
from django.db import models
class Site(models.Model):
name = models.CharField(max_length=50, unique=True)
def __str__(self):
return self.name
class Combo(models.Model):
username = models.CharField(max_length=50)
password = models.CharField(max_length=50)
dead = models.BooleanField(default=False)
timestamp = models.DateTimeField(auto_now_add=True)
siteID = models.ForeignKey(Site, on_delete=models.PROTECT)
class Meta:
unique_together = ('username','siteID')
def __str__(self):
return f"{self.username}:{self.password}#{self.siteID.name}"
When creating a view, I want to get the Combo objects, but I want to sort them first by site name, then username.
I tried to create the view, but get errors about what fields I can order by Cannot resolve keyword 'Site' into field. Choices are: dead, id, password, siteID, siteID_id, timestamp, username
def current(request):
current = Combo.objects.filter(dead=False).order_by('Site__name','username')
return render(request, 'passwords/current.html',{'current':current})
Since I'm not necissarily entering the sites into the database in alphabetical order, ordering by siteID wouldn't be useful. Looking for some help to figure out how to return back the list of Combo objects ordered by the Site name object then the username.

You can order this by siteID__name:
def current(request):
current = Combo.objects.filter(dead=False).order_by('siteID__name','username')
return render(request, 'passwords/current.html',{'current':current})
since that is the name of the ForeignKey. But that being said, normally ForeignKeys are not given names that end with an ID, since Django already adds an _id suffix at the end for the database field.
Normally one uses:
class Combo(models.Model):
# …
site = models.ForeignKey(Site, on_delete=models.PROTECT)
if you want to give the database column a different name, you can specify that with the db_column=… parameter [Django-doc]:
class Combo(models.Model):
# …
site = models.ForeignKey(
Site,
on_delete=models.PROTECT,
db_column='siteID'
)

De-serializing many to many field with a through table in DRF

I am working on developing a Trello-like website with Django Rest Framework.
I want to add selected users to BoardAccess model, a through table for User model and Board model, two of which are in Many to Many relationship. Being added to BoardAccess table will mean that the respective users will be having access to matching boards.
Models.py
class Board(models.Model):
name = models.CharField(max_length=50)
access_granted = models.ManyToManyField(User, through='BoardAccess', related_name='access_boards')
team = models.ForeignKey(Team, on_delete=models.CASCADE) # a team can have many boards
class BoardAccess(models.Model):
user = models.ForeignKey(User, on_delete=models.SET_NULL, null=True)
board = models.ForeignKey('Board', on_delete=models.CASCADE)
For User, I am currently using Django's default Auth User model and extending it with a Profile model via OneToOne Field.
Serializers.py
class BoardAccessSerializer(serializers.ModelSerializer):
members = serializers.SerializerMethodField()
added_users = # ???
new_name = serializers.CharField(
write_only=True, required=False, source='name') # in case of requests for renaming the board
def get_members(self, instance):
members = User.objects.filter(profile__team=instance.team)
return UserBoardSerializer(members, many=True).data
I would like to know what field / relations / another serializer should be assigned to added_users, which I think should be write_only=True, in order to successfully de-serialize input from the client-side containing primary keys of selected users.
get_members() method is used to first display information of all team members, from which a client will select users to be added to the board.
Views.py
class BoardAccessRetrieveUpdateAPIView(generics.RetrieveUpdateAPIView):
serializer_class = BoardAccessSerializer
permission_classes = [IsAuthenticated]
def get_queryset(self):
team_id = self.kwargs.get('team_id')
team = get_object_or_404(Team, id=team_id)
queryset = Board.objects.select_related(
'team').prefetch_related(
'access_granted').filter(team=team)
return queryset
I am new to DRF, so there may be a lot of points to be improved from the above. I would really appreciate every help!!

You can override the update method in your serializer, and get the user ids from the client side from initial_data
def update(self, instance, validated_data):
// do the actions on create
users = self.initial_data.get('users')
instance.access_granted.add(*users)
instance.save()
return instance
Also when using ModelSerializer have to add Meta class:
class BoardAccessSerializer(serializers.ModelSerializer):
class Meta:
model = Board
fields = "__all__"

Displaying fields other than pk in a Django Form with a ModelChoiceField

I am building a website where users can upload files and can attach uploads to projects that they created beforehand. The upload is done with a django form where the user can specify the title, comments, etc... There is also a dropdown list where the user can choose from the existing projects that he created (list of projects is dependent on user)
As of now the dropdown only shows the (autogenerated) project id which is the pk of the model Project.
I want the dropdown to show the names of the projects and not the project ID which is not very meaningful for the user.
I have already tried
to_field_name='name'
but that didn't work
I have also tried
Project.objects.filter(user=user).values_list('name')
or
Project.objects.filter(user=user).values('name')
the last two options show the project name in {'projectname} but when I select them and submit the form the error "Select a valid choice. That choice is not one of the available choices."
This is my code:
models.py
class Upload(models.Model):
user = models.ForeignKey(User, on_delete=models.SET_NULL, null=True)
upload_date = models.DateTimeField(default=timezone.now)
comments = models.CharField(max_length=10000, null=True)
title = models.CharField(max_length=10000, null=True)
project = models.CharField(max_length=99, default='--None--')
forms.py
class UploadForm(ModelForm):
project = ModelChoiceField(label='Select Project', queryset=Project.objects.all(), to_field_name='name',
empty_label='--Select Project--')
def __init__(self, *args, **kwargs):
user = kwargs.pop('user', None)
super(UploadForm, self).__init__(*args, **kwargs)
if user is not None:
self.fields['project'].queryset = Project.objects.filter(user=user)
class Meta:
model = Upload
fields = ['title', 'project', 'upload_date', 'comments']

According to docs
The str() method of the model will be called to generate string representations of the objects for use in the field’s choices. To provide customized representations, subclass ModelChoiceField and override label_from_instance. This method will receive a model object and should return a string suitable for representing it.
https://docs.djangoproject.com/en/2.2/ref/forms/fields/#modelchoicefield
so you should define __str__() method for Project model e.g.
def __str__(self):
return self.name

Trying to extend AbstractUser to create multiple user types in Django

So I have been searching all around the internet for a full example of how to user AbstractUser when u have at least 2 different models. Didn't find anything conclusive.. at least that would work on latest version of Django (2.0.1).
I have 2 models, teacher and student, and registration needs to be different. Besides username, email, name and surname, I need for example, for the student, to upload a profile picture, email, phone, student_ID. And for teacher, bio, academic title and website. Did I start good ? What is the right approach ?
class Profile(AbstractUser):
photo = models.ImageField(upload_to='students_images')
email = models.EmailField()
phone = models.CharField(max_length=15, )
class Student(Profile):
student_ID = models.CharField(unique=True, max_length=14,
validators=[RegexValidator(regex='^.{14}$',
message='The ID needs to be 14 characters long.')])
def __str__(self):
return self.name
class Teacher(Profile):
academic_title = models.CharField(max_length=30)
bio = models.TextField()
website = models.URLField(help_text="E.g.: https://www.example.com", blank=True)

Your goals can be accomplished using a 'Profile' pattern. You don't necessarily need to use a custom user model for this. But you need to have a single common model to for authentication; you can use the builtin django user for this or a custom class... Your Student and Teacher models should be OnetoOne relationships. This is the recommended solution per the documentation.
If you wish to store information related to User, you can use a OneToOneField to a model containing the fields for additional information. This one-to-one model is often called a profile model, as it might store non-auth related information about a site user.
In your case, you may do something like this:
class StudentProfile(models.Model):
user = models.OneToOneField('User', related_name='student_profile')
# additional fields for students
class TeacherProfile(models.Model):
user = models.OneToOneField('User', related_name='teacher_profile')
# additional fields for teachers
Then you can create your registration forms based on these profile models.
class StudentResistrationForm(forms.ModelForm):
class Meta:
model = StudentProfile
fields = (...)
class TeacherRegistrationForm(forms.ModelForm):
class Meta:
model = TeacherProfile
fields = (...)
You can create the user instance to which the profile is related to at the same time you create the profile. You might do this with formsets, for example.

add
class Meta:
abstract = True
to profile model
and change AbstractUser to models.Model

Building a django queryset over foreign key and onetoone

I have some two models (in different apps/models.py files) related with User:
class Profile(models.Model):
user = models.OneToOneField(settings.AUTH_USER_MODEL, null=False)
...
class CourseStudent(models.Model):
user = models.ForeignKey(settings.AUTH_USER_MODEL)
semester = models.ForeignKey(Semester)
...
I am trying to get a queryset of all profiles that have at least one course in the current semester.
How can I generate a queryset of profiles, where profile.user has at least one CourseStudent instance, and filtered so that coursestudent.semester=current_semester?
Since a student may have multiple courses in the semester, the duplicates also need to be removed (unique profiles only in the queryset)
EDIT: I am using postgresql and trying to figure out if I need to use distinct with an argument.

Not tested. Maybe you should try
class Profile(models.Model):
user = models.OneToOneField(settings.AUTH_USER_MODEL, null=False)
...
class CourseStudent(models.Model):
user = models.ForeignKey(settings.AUTH_USER_MODEL, related_name="course_student")
semester = models.ForeignKey(Semester)
Profile.objects.filter("what_you_want").exclude(user__courser_student=None).distinct()