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Find entities for specific user through multiple tables in Django Admin

I searched through stackoverflow about this particular scenario, but could not find a concrete answer, so i'm posting this.
So my problem is that i need to display specific records to a specific user in Django Admin. I'm aware that i can get the concrete logged in user through the get_queryset method extracting it from the request object. But the issue is i need to look through 6 tables to get to the information about the user of the recommendations so i could know which recommendation to display to him.
For example, if the records i need to display come from a Recommendation table, it has a reference to TableA, which has a reference to TableB .... which has a reference to TableF which has a reference to the User.
I'm aware i could do this by executing a plain SQL query with multiple joins, but my guess is that there must be a pythonic or Django sophisticated solution to this. But i may be wrong.
The model is unfortunately not in my control, nor i can change it, so i'm left to work with the state of the model that there is.
Thanks in advance.
EDIT: Unfortunately, i can't share details of it, but i can share the general look of it. So i think this should be enough to have a picture of my problem.
from django.db import models
from django.contrib.auth.models import User
class TableF(models.Model):
information = models.CharField(max_length=256, null=False)
user = models.ForeignKey(User, on_delete=models.CASCADE)
class TableE(models.Model):
information = models.CharField(max_length=256, null=False)
tableF = models.ForeignKey(TableF, on_delete=models.CASCADE)
class TableC(models.Model):
information = models.CharField(max_length=256, null=False)
tableEs = models.ManyToManyField(TableE, through='TableD')
class TableD(models.Model):
information = models.CharField(max_length=256, null=False)
tableC = models.ForeignKey(TableC, on_delete=models.CASCADE)
tableE = models.ForeignKey(TableE, on_delete=models.CASCADE)
class TableA(models.Model):
information = models.CharField(max_length=256, null=False)
tableCs = models.ManyToManyField(TableC, through='TableB')
class TableB(models.Model):
information = models.CharField(max_length=256, null=False)
tableA = models.ForeignKey(TableA, on_delete=models.CASCADE)
tableC = models.ForeignKey(TableC, on_delete=models.CASCADE)
class Recommendation(models.Model):
information = models.CharField(max_length=256, null=False)
tableA = models.ForeignKey(TableA, on_delete=models.CASCADE)

you can use a middleware to include de user to the thread locals and catch this user from get_queryset in the model manager.
from threading import local
_thread_locals = local()
def get_current_user():
return getattr(_thread_locals, 'user', None)
class ThreadLocals(object):
#staticmethod
def process_request(request):
_thread_locals.user = getattr(request, 'user', None)
in the settings
MIDDLEWARE = [
...
'path.to.file.ThreadLocals',
]
from your.path import get_current_user
class TableFManager(models.Manager):
def get_queryset(self):
return super().get_queryset().filter(creator=get_current_user())
class TableF(models.Model):
information = models.CharField(max_length=256, null=False)
user = models.ForeignKey(User, on_delete=models.CASCADE)
objects = TableFManager()

another less invasive option could be to rewrite the get_queryset in the admin class. there you already have the user in the request

def get_rec_user(user):
tes = TableE.objects.filter(tableF__in=TableF.objects.filter(user=user))
aes = TableB.objects.filter(tableE__in=tes).values_list('tableA_id', flat=True)
return Recommendation.objects.filter(
tableA__in=TableA.objects.filter(id__in=aes)
)

Save multiple values in one field (Django)

The problem:
I have a model, which is referencing the basic User model of django. Right now, if I submit the form Django updates my database by replacing the existing data with the new one. I want to be able to access both of them. (In weight and date field)
Models file:
I saw other posts here, where they solved a problem by specifying a foreign key, but that doesn't solve it for me.
from django.db import models
from django.contrib.auth.models import User
from django.db.models.signals import post_save
from django.dispatch import receiver
# Create your models here.
class Profile(models.Model):
user = models.ForeignKey(User, on_delete=models.CASCADE)
weight = models.FloatField(max_length=20, blank=True, null=True)
height = models.FloatField(max_length=20, blank=True, null=True)
date = models.DateField(auto_now_add=True)
def __str__(self):
return self.user.username
#receiver(post_save, sender=User)
def save_user_profile(sender, instance, created, **kwargs):
if created:
Profile.objects.create(user=instance)
Views file:
This is where I save the data that I get from my form called WeightForm
from django.shortcuts import render
from django.contrib.auth.models import User
from django.http import JsonResponse
from django.shortcuts import get_object_or_404
from users import models
from users.models import Profile
from .forms import WeightForm
def home(request):
form = WeightForm()
if request.is_ajax():
profile = get_object_or_404(Profile, id = request.user.id)
form = WeightForm(request.POST, instance=profile)
if form.is_valid():
form.save()
return JsonResponse({
'msg': 'Success'
})
return render(request, 'Landing/index.html',{'form':form})
What I tried:
I used to have a OneToOneField relation with this model, but as you can see I changed it to foreignkey, according to answers I saw on this site.
Thanks if you've gotten this far in my mess :D

I didn't understood exactly what you mean by "I want to be able to access both of them. (In weight and date field)" but I guess you want user to be able to see their previous data of weight and Date also, so you can try doing this:
In your models.py do try doing this,
class Profile(models.Model):
user_id = models.AutoField(primary_key=True)
user = models.ForeignKey(User, on_delete=models.CASCADE)
height = models.FloatField(max_length=20, blank=True, null=True)
def __str__(self):
return self.user.username
class UserData(models.Model):
Data_id = models.AutoField(primary_key=True)
user_id = models.ForeignKey(Profile, on_delete=models.CASCADE)
weight = models.FloatField(max_length=20, blank=True, null=True)
date = models.DateField(auto_now_add=True)
then u can have seperate forms for both the models and use them combined.

You can make a workaround
Create new model which would include something like "version"
Reference to version with foreign key
class ProfileChange(models.Model):
Date = models.DateField(default=datetime.datetime.today().strftime('%Y-%m-%d'))
#classmethod
def create(cls):
object = cls()
return object
class Profile(models.Model):
version = models.ForeignKey(ProfileChange,on_delete=models.CASCADE)
Unfortunately, you could see only one ProfileChange a day. If you want to see more of them, instead of models.DataField use models.IntegerField

the model field's form disappears in django admin

I have two models, which are User and Record. Each has several fields.
from django.db import models
class User(models.Model):
openid = models.CharField(max_length=20)
nickname = models.CharField(max_length=20,null=True)
def __str__(self):
return self.nickname
class Record(models.Model):
expression = models.CharField(max_length=100)
user = models.ForeignKey(User)
time = models.DateTimeField(auto_now_add=True)
def __str__(self):
return self.expression
I register them in admin.py
from django.contrib import admin
from .models import User,Record
class RecordAdmin(admin.ModelAdmin):
list_display = ('expression','user','time')
class UserAdmin(admin.ModelAdmin):
empty_value_display = "空"
list_display = ('openid','nickname')
admin.site.register(User,UserAdmin)
admin.site.register(Record,RecordAdmin)
it works well in django admin initially. but one day, the fields of the Record model disppeared. It looks like
.
No field displays. It makes me unable to modify or add the values of the Record model. The other model User works well and all data exists in database. So why?

I think you just have to add on_delete=models.CASCADE in your ForeignKey Field. When you are using this kind of field, you have to specify the comportment when you make an update, a delete or anything else on this field.
So your script should be like this :
class Record(models.Model):
expression = models.CharField(max_length=100)
user = models.ForeignKey(User, on_delete=models.CASCADE)
time = models.DateTimeField(auto_now_add=True)
def __str__(self):
return self.expression
This is the result :
Edit :
You can also modify null=True by default=null
class User(models.Model):
openid = models.CharField(max_length=20)
nickname = models.CharField(max_length=20,default=null)
def __str__(self):
return self.nickname

How to allow only one User to see "UpdateView"?

I have a Users and Jobs. If some User creates a Job, then and only then he/she can edit some information of this Job.
So he visits the url .../job/update/<id>. If the Job is created by him (the User is a ForeignKey in Job, then he can modify data. Otherwise he gets 404 error.
In view function, I would probably get current Users id and compare this id to Jobs ForeignKey.
But there are many patterns and shortcuts in class views so I'm curious how to do that this way.
class EditOrderView(UpdateView):
model = Job
fields = ['language_from','language_to','level','short_description','notes',
'text_to_translate','file']
template_name = 'auth/jobs/update-order.html'
class Job(models.Model):
customer = models.ForeignKey(User, related_name='orders', help_text=u"Zákazník")
translator = models.ForeignKey(User, related_name='jobs', null=True, blank=True, help_text=u"Prekladateľ")
price = models.FloatField(null=True, blank=True, help_text=u"Cena")
language_from = models.ForeignKey(Language, related_name='jobs_from', null=True)
language_to = models.ForeignKey(Language, related_name='jobs_to', null=True)
...

It looks like you can override .get_object() method and include your own logic:
from django.shortcuts import get_object_or_404
class EditOrderView(UpdateView):
model = Job
...
def get_object(self, queryset=None):
return get_object_or_404(self.model, pk=self.kwargs["pk"], customer=self.request.user)

How to execute CASCADE on delete?

I have this model in Django, where a person has the same information from the user provided by Django plus a little bit more information. When I create a new person it requires to create a new user also, that's fine. But when I delete a person the user still remains on my database. What am I missing here ? I would like to delete the user too.
class Person(models.Model):
user = OneToOneField(User)
gender = CharField(max_length=1, choices=GenderChoices, blank=True, null=True)
birth_date = DateField(blank=True, null=True)
def __unicode__(self):
return self.user.username

Try to override the delete method on the model (code not tested):
class Person(models.Model):
user = OneToOneField(User)
gender = CharField(max_length=1, choices=GenderChoices, blank=True, null=True)
birth_date = DateField(blank=True, null=True)
def __unicode__(self):
return self.user.username
def delete():
theuser = User.objects.get(id=user)
theuser.delete()
I have found some relevant documentation about CASCADE usage in Django here.