Django — Queries

Basic Queries

# Get all objects
posts = Post.objects.all()

# Filter
posts = Post.objects.filter(published=True)

# Get single object
post = Post.objects.get(pk=1)

# Get or create
post, created = Post.objects.get_or_create(
    title='My Post',
    defaults={'content': 'Hello'}
)

QuerySet Methods

Method	Description
all()	All objects
filter()	Filter by conditions
exclude()	Exclude by conditions
get()	Get single object
order_by()	Order results
distinct()	Remove duplicates
count()	Count objects
exists()	Check if any exist
first()	Get first object
last()	Get last object

Filtering

# Exact match
Post.objects.filter(title='Hello')

# Contains
Post.objects.filter(title__contains='hello')

# Case-insensitive contains
Post.objects.filter(title__icontains='hello')

# Greater than
Post.objects.filter(pk__gt=1)

# In list
Post.objects.filter(pk__in=[1, 2, 3])

# Date filters
Post.objects.filter(created_at__year=2025)

Chaining Queries

posts = Post.objects.filter(
    published=True
).filter(
    author__name='John'
).order_by('-created_at')[:10]

Complex Queries

from django.db.models import Q

posts = Post.objects.filter(
    Q(title__icontains='hello') | Q(content__icontains='hello')
)

Mini Practice

1. Perform basic queries
2. Use filter and exclude
3. Chain query methods
4. Use Q objects for complex queries

Up Next

Continue with Migrations — database schema management.