Understanding select_related and prefetch_related in Django ORM

 When working with Django ORM, optimizing database queries is crucial for performance, especially when dealing with related objects. Django offers two methods, select_related() and prefetch_related(), which are designed to reduce the number of database hits when fetching related data. But what exactly is the difference between these two methods, and when should you use each? Let’s dive deeper into their functionalities.

What is select_related?

The select_related() method is designed to work with foreign-key relationships. It performs an SQL join and retrieves data in a single query. This is highly efficient when you need to fetch related objects in one-to-one or foreign-key relationships because it avoids making multiple queries to the database.

When you use select_related(), Django generates a JOIN clause in the SQL query. This means that the related object’s data is fetched along with the original query, reducing the number of queries executed.

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