Some functions are hard as well as boring to code each and every time. But Django users don’t have to worry about that because Django has some awesome built-in functions to make our work easy and enjoyable. Let’s discuss get_object_or_404() here.
What is get_object_or_404 in Django?
get_object_or_404 is a convenient shortcut function provided by Django, which is used for getting an object from a database using a model’s manager and raising an Http404 exception if the object is not found. It’s commonly used in views to get a single object based on a query and handle the case where the object doesn’t exist.
How to use get_object_or_404() in a Django Project?
This function calls the given model and gets an object from that if that object or model doesn’t exist it raises a 404 error.
Example: Suppose we want to fetch 3rd product from the product model then we can use:
Python3
# import get_object_or_404()from django.shortcuts import get_object_or_404# defining viewdef product_view(request): # retrieving product (pk is primary key) product = get_object_or_404(Products, pk=3) |
This is the advantage of Django if you hardcode that then you have to write this much line of code.
Python3
# import Http404from django.http import Http404# defining viewdef product_view(request): # try except logic try: product = Products.objects.get(pk=1) except Products.DoesNotExist: raise Http404("Given query not found....") |
Using get_object_or_404() with QuerySet
QuerySet instance is used to filter data while fetching from the database. For example, we want to fetch only shoes then we can write:
queryset = Products.objects.filter(type='shoes')
get_object_or_404(queryset)
We can simplify above example by a single line:
get_object_or_404(Products, type='shoes')
