Question

Problem Statement: Make following query in Django API.

Table : Product

Fields:

id  int   primary_key

class_id   int

class_content    CharField

Each class_id have multiple class content.

For two different class id there are same as well as different class_content.

I want to list the difference between two class_id:

Here is how I can create query in raw SQL:

eg: generate difference between class_id = 1 and class_id =2

Query:

SELECT * FROM Product 

WHERE class_id = 1 && class_content NOT IN

(SELECT class_content FROM Product WHERE class_id = 2);

This query works fine and gives the difference between class_id 1 and 2.
I want this query to be executed in django, I couldn’t draw same result from django APIs.

Answer 1

This should work:

Product.objects.filter(class_id=1).exclude(class_content__in=Product.objects.filter(class_id=2).values_list('class_content', flat=True))