Adding JSON field in Django models

In this article, we will see how to add JSON fields to our Django models. JSON is a simple format to store data in key-value pairs using curly braces. JSON fields are particularly useful when you need to store flexible, unstructured data like user preferences, metadata, or configuration settings.

First, create a Django project and an app. Make sure to add your app to INSTALLED_APPS, set up URLs, and configure your basic project structure.

Modern Approach (Django 3.1+)

Django 3.1 and later versions include native JSON field support, eliminating the need for third-party packages ?

from django.db import models

class StudentData(models.Model):
    name = models.CharField(max_length=100)
    standard = models.CharField(max_length=100)
    section = models.CharField(max_length=100)
    metadata = models.JSONField(default=dict)
    
    def __str__(self):
        return self.name

Legacy Approach (Django < 3.1)

For older Django versions, you need to install the django-jsonfield package ?

pip install django-jsonfield

Then create your model ?

import jsonfield
from django.db import models

class StudentData(models.Model):
    name = models.CharField(max_length=100)
    standard = models.CharField(max_length=100)
    section = models.CharField(max_length=100)
    the_json = jsonfield.JSONField()
    
    def __str__(self):
        return self.name

Admin Configuration

Register your model in admin.py to manage it through Django admin ?

from django.contrib import admin
from .models import StudentData

@admin.register(StudentData)
class StudentDataAdmin(admin.ModelAdmin):
    list_display = ['name', 'standard', 'section']

Database Migration

Run these commands to create and apply migrations ?

python manage.py makemigrations
python manage.py migrate
python manage.py createsuperuser

Using JSON Fields

You can store and query JSON data directly ?

# Creating an instance with JSON data
student = StudentData.objects.create(
    name="John Doe",
    standard="10th",
    section="A",
    metadata={
        "hobbies": ["reading", "swimming"],
        "grades": {"math": 95, "science": 87},
        "contact": {"email": "john@example.com"}
    }
)

# Querying JSON field data
students_with_reading = StudentData.objects.filter(
    metadata__hobbies__contains="reading"
)

Comparison

Conclusion

Use Django's native JSONField for modern projects (Django 3.1+) as it provides better performance and database support. For legacy projects, django-jsonfield remains a viable option for storing flexible JSON data.