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How to create a view for a nested serializer with foreign keys in django rest framework?

I got this code, but I can't find a way to create a view that retrieve the allergies a patient has.
class Patient(models.Model):
user = models.OneToOneField(User, related_name='patient', on_delete=models.CASCADE)
id_type = models.CharField(max_length=300)
id_number = models.CharField(max_length=300)
creation_date = models.DateField(default=datetime.date.today)
class Allergie(models.Model):
name = models.CharField(max_length=300, default="X")
class PatientAllergies(models.Model):
patient = models.ForeignKey(Patient, related_name="patient_allergies", on_delete=models.CASCADE)
allergie = models.ForeignKey(Allergie, on_delete=models.CASCADE, null=True)
professional_contract = models.ForeignKey(ProfessionalContract, null=True ,on_delete=models.CASCADE)

You can span a ManyToManyField relation over your PatientAllergies model that acts as a junction table:
class Patient(models.Model):
user = models.OneToOneField(User, related_name='patient', on_delete=models.CASCADE)
id_type = models.CharField(max_length=300)
id_number = models.CharField(max_length=300)
creation_date = models.DateField(auto_now_add=True)
allergies = models.ManyToManyField(
'Allergie',
through='PatientAllergies'
)
# …
You can then for a Patient object p with:
p.allergies.all()
An alternative is to filter the Allergie objects with:
Allergie.objects.filter(patientallergies__patient=p)
or with the ManyToManyField:
Allergie.objects.filter(patient=p)

problem with multiple user dependent on each other in Django

I am working with some custom-made user models in Django. They are the following:
myCustomeUser responsible for the primary identity of a user
Industry is a user that will link with OneToOneField to the myCustomeUser
Employee is another user account, which will FK to the myCustomeUser and FK to Industry
my models.py:
class myCustomeUser(AbstractUser):
id = models.AutoField(primary_key=True)
username = models.CharField(max_length=20, unique="True", blank=False)
password = models.CharField(max_length=20, blank=False)
is_Employee = models.BooleanField(default=False)
is_Industry = models.BooleanField(default=False)
class Industry(models.Model):
user = models.OneToOneField(myCustomeUser, on_delete=models.CASCADE, primary_key=True, related_name='industry_releted_user')
name = models.CharField(max_length=200, blank=True)
owner = models.CharField(max_length=200, blank=True)
license = models.IntegerField(null=True, unique=True)
industry_extrafield = models.TextField(blank=True)
Now I need to write the model of Employee. There are some conditions also:
It should contain name, National ID, gmail, rank, employee_varified, named fields
This will inherit the myCustomeUser and Industry both
The Industry account user will primarily entry all the data of Employee in the database, except username and password(which are inherited from myCustomeUser)
Later on, the Employee will search his National ID given by the Industry and finish the registration process by creating his username and password.
I have tried the Employee model like this:
class Employee(models.Model):
user = models.ForeignKey(myCustomeUser,primary_key=True, null=True, on_delete=models.CASCADE)
industry = models.ForeignKey(Industry, on_delete=models.CASCADE)
National_ID = models.IntegerField(null=True, blank=False, unique=True)
name = models.CharField(max_length=200, blank=False, null=True)
gmail = models.EmailField(null=True, blank=False, unique=True)
rank = models.CharField(max_length=20, blank=False, null=True)
employee_varified = models.BooleanField(default=False, blank=True, null=True)
But the problem with this model is I cannot create any Employee object without giving user (that means username and password), But the Industry user needs to entry their Employee's data, before complete the Employee's registration.
how can I write my Employee model to solve this problem?

If you can't guarantee that a related object will exist when you create an object, you can make the relationship(s) optional.
So in your case, I'd create your model more like;
class Employee(models.Model):
user = models.ForeignKey(
myCustomeUser,
blank=True,
null=True,
on_delete=models.CASCADE
)
industry = models.ForeignKey(
Industry,
blank=True,
on_delete=models.CASCADE
)
national_id = models.IntegerField(
null=True,
blank=False,
unique=True
)
name = models.CharField(
max_length=200,
blank=False,
null=True
)
# ... etc
You may also benefit from having a look through the following site which might help you learn a thing or two about django
https://www.django-antipatterns.com/

Django API ManyToMany on existing databse not working

at the moment I try to get recipes from my API. I have a Database with two tables one is with recipes and their ids but without the ingredients, the other table contains the ingredients and also the recipe id. Now I cant find a way that the API "combines" those. Maybe its because I added in my ingredient model to the recipe id the related name, but I had to do this because otherwise, this error occurred:
ERRORS:
recipes.Ingredients.recipeid: (fields.E303) Reverse query name for 'Ingredients.recipeid' clashes with field name 'Recipe.ingredients'.
HINT: Rename field 'Recipe.ingredients', or add/change a related_name argument to the definition for field 'Ingredients.recipeid'.
Models
from django.db import models
class Ingredients(models.Model):
ingredientid = models.AutoField(db_column='IngredientID', primary_key=True, blank=True)
recipeid = models.ForeignKey('Recipe', models.DO_NOTHING, db_column='recipeid', blank=True, null=True, related_name='+')
amount = models.CharField(blank=True, null=True, max_length=100)
unit = models.CharField(blank=True, null=True, max_length=100)
unit2 = models.CharField(blank=True, null=True, max_length=100)
ingredient = models.CharField(db_column='Ingredient', blank=True, null=True, max_length=255)
class Meta:
managed = False
db_table = 'Ingredients'
class Recipe(models.Model):
recipeid = models.AutoField(db_column='RecipeID', primary_key=True, blank=True) # Field name made lowercase.
title = models.CharField(db_column='Title', blank=True, null=True, max_length=255) # Field name made lowercase.
preperation = models.TextField(db_column='Preperation', blank=True, null=True) # Field name made lowercase.
images = models.CharField(db_column='Images', blank=True, null=True, max_length=255) # Field name made lowercase.
#ingredients = models.ManyToManyField(Ingredients)
ingredients = models.ManyToManyField(Ingredients, related_name='recipes')
class Meta:
managed = True
db_table = 'Recipes'
When there is no issue it has to be in the serializer or in the view.
Serializer
class IngredientsSerializer(serializers.ModelSerializer):
# ingredients = serializers.CharField(source='ingredients__ingredients')
class Meta:
model = Ingredients
fields = ['ingredient','recipeid']
class FullRecipeSerializer(serializers.ModelSerializer):
ingredients = IngredientsSerializer(many=True)
class Meta:
model = Recipe
fields = ['title','ingredients']
View
class FullRecipesView(generics.ListCreateAPIView):
serializer_class = FullRecipeSerializer
permission_classes = [
permissions.AllowAny
]
queryset = Recipe.objects.all()
This is at the moment my output
But I want e.g. the recipe with id 0 and all the ingredients which have also recipe id 0.
I really hope that you can help me. Thank you so much!

Rename ingredients to some other name in FullRecipeSerializer. It conflicts with ingredients in Recipe model. This should solve your issue. For example
class FullRecipeSerializer(serializers.ModelSerializer):
ingredients_recipe = IngredientsSerializer(many=True, source= 'ingredientid')
class Meta:
model = Recipe
fields = ['title','ingredients_recipe']

How to do many to one relationship in Django

I am doing a many to one relationship but I get a prompt that the field person in the report is without a default.
I tried setting the default to an empty space, I get an IntegrityError: NOT NULL constraint failed
class Person(models.Model):
person_name = models.CharField(max_length=255)
person_location = models.CharField(max_length=255, null=True)
classReport (models.Model):
person = models.ForeignKey(
Person, related_name='people', default="", on_delete=models.CASCADE)
product_name = models.CharField(max_length=255)
product_description = models.CharField(max_length=255)

Django postgres migrate models column discount.category_name_id does not exist

Hi i'm trying to combine Django backend and postgresql database together.
Here is my database tables:
My models.py in Django
from django.db import models
# Create your models here.
class Categories(models.Model):
id = models.IntegerField(primary_key=True)
name = models.TextField(null=True, unique=True)
class Meta:
db_table = 'categories'
def __str__(self):
return self.name
class Website(models.Model):
id = models.IntegerField(primary_key=True)
site = models.TextField(null=True, unique=True)
class Meta:
db_table= 'website'
def __str__(self):
return self.site
class Discount(models.Model):
id = models.IntegerField(primary_key=True)
product_name = models.TextField()
product_price = models.TextField()
product_old_price = models.TextField()
product_link = models.TextField()
category_name = models.ForeignKey(Categories, on_delete=models.CASCADE, null=True, to_field='name')
product_site = models.ForeignKey(Website, on_delete=models.CASCADE, null=True, to_field='site')
product_image = models.TextField()
class Meta:
db_table = 'discount'
def __str__(self):
return self.product_name
I managed to link Django and postgresql together following tutorials but when i try to migrate the database for the first time it come with this error :
column discount.category_name_id does not exist LINE 1:
..."."product_old_price", "discount"."product_link", "discount"...
^ HINT: Perhaps you meant to reference the column "discount.category_name".
i though i linked my foreign key from discount.category_name to categories.name with to_field='name' in the ForeignKeyField but somehow it used the discount.category_name_id ? i don't know where the category_name_id is, it's not in my tables
Any help would be appreciate!

Below field is not reflected in the database, please check you db fields name if not then create the one dummy migration and write the script for that
category_name = models.ForeignKey(Categories, on_delete=models.CASCADE, null=True, to_field='name')

I managed to fixed it by adding
db_column='category_name'
to the ForeignKey field
It seems that i need to specific what column that actually is a Foreign key in my Postgresql tables to the ORM
category_name = models.ForeignKey(Categories, on_delete=models.CASCADE, null=True, to_field='name', db_column='category_name')
product_site = models.ForeignKey(Website, on_delete=models.CASCADE, null=True, to_field='site', db_column='product_site')