SQL is used by analysts, data scientists, product managers, designers and many others. These professionals have access to databases, but they don't always have the intuition and understanding to write efficient queries. In an effort to make my team write better SQL, I went over reports written by non-developers and code reviews, and gathered common mistakes and missed optimization opportunities in SQL.
SQL injection attacks are constantly ranked among the most common attacks against systems. While binding values is very common, I often find my self needing to being table and column names as well. This article will walk you through everything you need to know about SQL injections in Python.
Inspired by an actual incident we had in one of our systems caused by an "Export to Excel" functionality implemented in Python, we go through the process of identifying the problem, experimenting and benchmarking different solutions.
Getting the last value of a group in an aggregated query in PostgreSQL is a challenging task. In this article we present a simple way to get the first or last value of a group using group by.
Have you ever stopped to think what staff user can do in your Django admin site? Did you know staff users with misconfigured permissions on the user model can make themselves superusers? Permissive permissions to staff users can cause disastrous human errors at best, and lead to major data leaks and at worst.
Explore the best way to import messy data from remote source into PostgreSQL using Python and Psycopg2. The data is big, fetched from a remote source, and needs to be cleaned and transformed.
When a developer chooses Python, Django, or Django Rest Framework, it's usually not because of its blazing fast performance. All of this doesn't mean performance is not important. As this story taught us, major performance boosts can be gained with just a little attention, and a few small changes.
If you have a public facing Django site in multiple languages, you probably want to let Google and other search engines know about it.
If you ever had to maintain a traffic heavy Django site, you probably had to deal with graceful migrations. In the article I explain what atomic and reversible migrations are, how to execute "raw" SQL in migrations the right way, and how using a little known migration command we can completely alter the Django migrations built-in behavior.
How we cut a heavy admin dashboard response time in half with advanced SQL and some Django hackery. I recently had the pleasure of optimizing an old dashboard. The solution we came up with required some advanced SQL that Django does not support out of the box. In this article I present the solution, how we got to it, and a word of caution.