Python Django Queryset Filtering

In Django, QuerySet filtering allows you to retrieve only the data you need from the database. QuerySets help you filter, sort and organize your data efficiently, making it easy to interact with your models.

This article will explore how to filter datasets using Django’s filter(), exclude() and advanced filtering with Q objects, let's create a model named "user".

Define the User Model

In projectApp/models.py, define a User model with fields like user_name, city and country:

from django.db import models

class User(models.Model):
    user_name = models.CharField(max_length=20)
    city = models.CharField(max_length=20, blank=True, null=True)
    country = models.CharField(max_length=20, blank=True, null=True)

    def __str__(self):
        return self.user_name

Register the Model in Django Admin

To make the User model accessible in the Django Admin interface, register it in projectApp/admin.py:

from django.contrib import admin
from .models import User

admin.site.register(User)

Create a superuser to access the model through admin panel.

python manage.py createsuperuser

Suppose we have the following the entries in our User model:

QuerySet Filtering Examples

Now that we have our User model, let’s explore how to filter data using QuerySets.

1. Filtering All Users:

To retrieve all users from a specific country, use filter():

users = User.objects.filter(country='India')

This retrieves all users where the country is 'India':

2. Excluding Specific Records:

To exclude records that match a condition, use exclude():

users = User.objects.filter(country='India').exclude(city='Mumbai')

This retrieves all users from India, excluding those from Mumbai.

3. Using Q Objects for Advanced Filtering:

Q objects allow for more complex queries, like OR conditions:

from django.db.models import Q

users = User.objects.filter(Q(country='India') | Q(city='New York'))

This returns users who are from either India or New York.

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Article Tags :

• Technical Scripter
• Python
• Technical Scripter 2022

Practice Tags :

• python