Back
Sep 23, 2010

OR and AND without django.db.models.Q

I just found out that orand andare defined for QuerySet. This means that to do queries union or intersection, you can do:

User.objects.filter(...) | User.objects.filter(...)
User.objects.filter(...) & User.objects.filter(...)

Subscribe for the news and updates

More thoughts
Apr 3, 2024Technology
Test Analysis at the Product Level

Test analysis is an essential and crucial activity in the testing process. A well-organized test analysis provides an adequate level of confidence in the overall effectiveness of the testing and contributes to the delivery of high-quality software.

Sep 21, 2020Technology
How to Optimize Django ORM Queries

Django ORM is a very abstract and flexible API. But if you do not know exactly how it works, you will likely end up with slow and heavy views, if you have not already. So, this article provides practical solutions to N+1 and high loading time issues. For clarity, I will create a simple view that demonstrates common ORM query problems and shows frequently used practices.

Mar 2, 2017Technology
API versioning with django rest framework?

We often handling API server updates including backwards-incompatible changes when upgrading web applications. At the same time we update the client part, therefore, we did not experience any particular difficulties.

Jan 22, 2017Technology
Django vs Rails Performance

This article is aimed for beginners, who are trying to choose between Ruby on Rails and Django. Let’s see which is fastest and why.

Apr 3, 2011Technology
Sprite cache invalidation

When we use css-sprites it's important to make browser cache them for longest period possible. On other hand, we need to refresh them when they are updated. This is especially visible when all icons are stored in single sprite. When it's outdated - entire site becomes ugly.

Feb 18, 2010Technology
User profiles with inheritance in Django

Usually users' profiles are stored in single model. When there are multiple user types, separation is made by some field like user_type.Situation is a little more complicated when different data is needed for each user type.In this article I'll describe how I solve this task.