using related_name in Django

In this Blog we are going to talk about, How to use the related_name parameter in Django. When we create any type of relating in Django, Django by Default creates a backward relating or you can say it is a reverse relation. with the related_name attribute, we can give a name to the reverse relation.

Let’s try to understand this with an example:-

from django.db import models
from django.contrib.auth.models import User
# Create your models here.

class Note(models.Model):
    user = models.ForeignKey(User,on_delete=models.CASCADE)
    content = models.TextField()

in the upper model, we have one too many relations, a user can create as many notes as many he wants. Lets’ try to access all the notes of a currently logged-in user

def get_notes(request):
    user = request.user
    notes = Notes.objects.filter(user = user)    
    context = {
        "notes":notes
    }
    return render(request, 'home.html',context)

Here we directly access all the notes of currently logged-in users using the Notes model, now let’s say I don’t want to use the Notes model to access notes of currently logged-in users, I want to access Notes for the currently logged-in user using reverse relation. We already know that Django by default creates reverse relations and we can use that relationship with the _set object. Here we are trying to get all the notes of currently logged-in users.

def get_notes(request):
    user = request.user   
    notes = user.notes_set.all()
    context = {
        "notes":notes
    }
    return render(request, 'home.html',context)

Here we can access all the todos of the currently logged-in users, using _set object.

Now let’s add the related_name attribute and see what changes and simplicity it provides.

from django.db import models
from django.contrib.auth.models import User
# Create your models here.

class Note(models.Model):
    user = models.ForeignKey(User,on_delete=models.CASCADE,related_name="notes")
    content = models.TextField()

In the above code we have added related_name = "notes" parameter.

def get_notes(request):

    user = request.user
    notes = user.notes.all()
    context = {
        "notes":notes
    }
    return render(request, 'home.html',context)

As you can see using the related name attribute make our code more readable, you can use the related name attribute in all types of model relations in Django. If you want to disable Django's default reverse relation then you can add related_name = “+” and this will disable Django's default reverse relation.

from django.db import models
from django.contrib.auth.models import User
# Create your models here.

class Note(models.Model):
    user = models.ForeignKey(User,on_delete=models.CASCADE,related_name="+")
    content = models.TextField()

this will disable Django's default relation.