How do I perform database joins in Django?

How do I perform database joins in Django?

In Django, you can perform database joins using the ORM. You can use methods like select_related and prefetch_related 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 model, you can do: Book.objects.select_related('author').all() to fetch books along with their authors in a single query.

What about prefetch_related? When should I use that?

prefetch_related is used for many-to-many relationships or when you want to fetch related objects in separate queries. For example: Author.objects.prefetch_related('books').all().

Are there any performance considerations I should be aware of?

Yes, using select_related can be more efficient for single-valued relationships, while prefetch_related is better for multi-valued relationships. Always analyze your queries to avoid N+1 problems.