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
One of our ongoing projects, Neptyne, introduces an Excel-like grid written in React. We used a library to apply virtual scroll to it, but we stumbled upon a problem with fixed rows and columns inside the grid. Here I would like to describe this problem, how it occurs, and how we handled it.
SQL is a fairly complicated language with a steep learning curve. For a large number of people who make use of SQL, learning to apply it efficiently takes lots of trials and errors. Here are some tips on how you can make your SELECT queries better. The majority of tips should be applicable to any relational database management system, but the terminology and exact namings will be taken from PostgreSQL.
We have reviewed the top web frameworks for server and client-side development and compared their pros and cons. Find out which one can be a great fit for your next project.
In this article we will tell you about the basics of working with GraphQL in Angular 2 environment with detailed example.
For any project there may be a need to use a database full-text search. We expect high speed and relevant results from this search. When we face such problem, we usually think about Solr, ElasticSearch, Sphinx, AWS CloudSearch, etc. But in this article we will talk about PostgreSQL. Starting from version 8.3, a full-text search support in PostgreSQL is available. Let's look at how it is implemented in the DBMS itself.
It appears that not everyone knows that in python you can create classes dynamically without metaclasses. I'll show an example of how to do it.So we've learned how to use custom QuerySet to chain requests:Article.objects.old().public()Now we need to make it work for related objects:user.articles.old().public()This is done using use_for_related_fields, but it needs a little trick.