This episode is about the basic statements needed to create, read, update and delete data in a database system. It is part of my SQL-Tutorial Motivation Let’s assume we work as a data scientist for Knight Industries. We want to help the Foundation of Law and Government to keep track of our operatives. We decide…
Sometimes your RDBMS does not allow you to do certain changes like updating a table without using a WHERE clause that uses a key column. When you are really sure what you want to do: SET SQL_SAFE_UPDATES = 0; Now the dirty brown magic can begin! Back to the SQL-Tutorial
Sometimes You screw up your database design and you have redundancies i.e. your database is not normalized. If You want to correct that: Subqueries for the rescue! In our example we have two tables which contain almost the same information: CREATE TABLE installed_device (`id` int, `device` text, `info` text); INSERT INTO installed_device (`id`, `device`, `info`)…
You can comment your queries with — This is a comment in SQL SELECT * FROM my_table — WHERE id = 1
I got confused by all the buzzwords: data science, machine learning, deep learning, neural nets, artificial intelligence, big data, and so on and so on. As an engineer I like to put some structure to the chaos. Inspired by Roadmap: How to Learn Machine Learning in 6 Months and Tetiana Ivanova – How to become…
Imagine that you come home from a party and you are stopped by the police. They ask you to take a drug test and you accept. The test result is positive. You are guilty. But wait a minute! Is it really that simple? In Germany about 2.8 million people consume weed on a regular basis,…
Keep it simple, stupid! When we first released our tool to the end user, we proudly named it v1.0.0. This is called semantic versioning – major.minor.patch Makes sense for libraries where a minor change e.g. 1.0.0 to 1.1.0 means interface compatibility, just some new functions. A major change e.g. 1.0.0 to 2.0.0 means “Attention, I…
Dealing with KnockoutJS I came across some newer features of the JavaScript language ES6 TL;DR: don’t use var anymore when You declare variables. Some examples:
Trying to contribute to the Flask plugin flask-login I just added these lines: if isinstance(duration, (int, long)): duration = timedelta(seconds=duration) Looking quite plausible, isn’t it? But lo and behold: it doesn’t work under Python 3.x. Dang! The reason: Python 2 has two integer types: int and long. In Python 3 there is only int, which…
After I’ve introduced You to Yarn I will show You more client side tools in this post. Grunt is a task runner which comes in handy for a lot of setup and configuring work e.g. concatenating and minimizing JavaScript or CSS files To get started You can add grunt via yarn to your project yarn…