Difference between queryset = Note.objects.all() and queryset = super().get_queryset() in Django views:

1. queryset = Note.objects.all():

This is a direct call to retrieve all instances of the Note model from the database. It bypasses any logic defined in the parent class and simply returns every record in the Note table.

• Usage: When you know exactly which model you want to query and want to directly set the queryset in your view, without relying on any inherited behavior from the parent class.
• Example:

class NoteListView(generics.ListAPIView):
    queryset = Note.objects.all()  # Directly set the queryset to fetch all Note objects
    serializer_class = NoteSerializer

In this example, all Note objects will be returned because you are explicitly setting Note.objects.all() as the queryset. No parent class behavior is involved here.

2. queryset = super().get_queryset():

This is used to call the get_queryset() method from the parent class (e.g., a generic view class). This allows you to reuse any logic or behavior that the parent class defines for building the queryset.

• Usage: When you want to inherit and possibly extend the behavior of the parent class’s get_queryset() method. By calling super().get_queryset(), you rely on the parent class to return the base queryset, and you can then modify or filter it further in the child class.
• Example:

class CustomNoteListView(generics.ListAPIView):
    serializer_class = NoteSerializer

    def get_queryset(self):
        # Get the base queryset from the parent class, which could involve some custom logic
        queryset = super().get_queryset()
        # Further filter the queryset
        return queryset.filter(active=True)

• In this example, super().get_queryset() calls the get_queryset() method from the parent class (likely ListAPIView), which might have some custom logic for fetching the base queryset. Then, you can apply additional filters (e.g., filter(active=True)).

Key Differences:

• Direct Query (Note.objects.all()):
  • You are directly specifying the queryset.
  • It ignores any logic from the parent class and always retrieves all objects from the database.
• Inherited Query (super().get_queryset()):
  • You are calling the parent class’s get_queryset() method, which may include additional behavior or filtering.
  • Allows you to build on or modify the logic defined in the parent class.

Example of When to Use Each:

• When to use Note.objects.all():
  • If your view is simple, and you always want to return all Note objects, you can directly set queryset = Note.objects.all()

class AllNotesView(generics.ListAPIView):
    queryset = Note.objects.all()  # Always return all Note objects
    serializer_class = NoteSerializer

When to use super().get_queryset():

• If you are working within a class hierarchy and want to extend or modify how the parent class generates the queryset (e.g., applying additional filters), use super().get_queryset() to inherit and build upon that logic.

class ActiveNotesView(generics.ListAPIView):
    def get_queryset(self):
        # Inherit the base queryset from the parent, then modify it
        queryset = super().get_queryset()
        return queryset.filter(active=True)  # Filter for only active notes

This way, you’re leveraging the behavior of the parent class while customizing the final queryset as needed.

Note

summary:

• No Need for super().get_queryset(): If you are not using any special logic from the parent class’s get_queryset(), there’s no need to call super().get_queryset(). You can directly return Note.objects.filter() in the overridden get_queryset() method.
• Simpler and Clearer: This approach avoids redundancy and makes it clear that the queryset is being filtered directly based on the current user and active status.

When to Use super().get_queryset():

You would use super().get_queryset() if the parent class’s get_queryset() method had some useful logic that you wanted to keep or build upon. For example, if the parent class was doing some default filtering or modifying the queryset in a meaningful way, you might want to call super().

But in this case, because you’re overriding the queryset logic entirely, it’s better to avoid super().get_queryset() and just define the custom filtering you need directly in get_queryset().