What is the N+1 query problem in Django?

What is the N+1 query problem in Django?

The N+1 query problem occurs when an application makes one query to retrieve a list of items and then makes an additional query for each item to retrieve related data. This can lead to performance issues.

How can I avoid the N+1 query problem?

You can avoid the N+1 query problem by using Django's select_related and prefetch_related methods to optimize your queries.

Can you give me an example of using select_related?

Sure! If you have a Book model with a foreign key to an Author, you can use Book.objects.select_related('author') to fetch books and their authors in a single query.

What about prefetch_related?

prefetch_related is used for many-to-many relationships or when you want to fetch related objects in separate queries but still optimize the number of queries. For example, Author.objects.prefetch_related('books').