Django Django 5

Question 1

What does Django's atomic() context manager guarantee for a block of database operations?

Accepted Answer

All succeed together or none are committed

Answer

transaction.atomic() wraps operations so they commit as a unit or roll back on error.

Question 2

Which queryset method counts rows efficiently in the database?

Accepted Answer

count()

Answer

count() issues a SQL COUNT query rather than loading all objects into memory.

Question 3

What does prefetch_related() optimize compared to select_related()?

Accepted Answer

Many-to-many and reverse foreign key relations

Answer

prefetch_related does separate lookups and joins in Python, ideal for many-to-many relationships.

Question 4

In a Django form, what does is_valid() do?

Accepted Answer

Run validation and populate cleaned_data

Answer

is_valid() validates submitted data and fills cleaned_data when validation passes.

Question 5

Which setting lists the apps Django loads for a project?

Accepted Answer

INSTALLED_APPS

Answer

INSTALLED_APPS registers applications so their models, templates, and admin are recognized.

Django Practice Test