SQL in Data Science

 
It's one of the most powerful tools we have at our disposal as data scientists. No, it's not deep learning. It's not statistics. It's not even Python. Structured Query Language (SQL) is used to manage data in a vast array of popular database engines, making it critical to access what data scientists (and others) are always on the hunt for: data.

You can't science the data without the data. Have you ever tried machine learning without a dataset? Do you often visualize nonexistent data? These things all need... you guessed it: data and patience. And while it can't help you with the patience, SQL can certainly help you get data out of relational databases, the place where all sorts of organizations decided decades ago to store it. Once in-hand, the sciencing of the data can begin.

And forget about data science altogether; SQL is one of the most popular languages out there, period. Why is SQL popular? There are all sort of reasons for this, a few important ones being that it is still the industry standard, it is used almost everywhere, and no one has come up with a proven better alternative. This all suggests that you should be learning SQL.

To help, KDnuggets' very own Abid Ali Awan has put together a fantastic SQL primer, which covers some of the important first steps in your SQL journey.

You can download the cheatsheet here.

Getting Started with SQL Cheatsheet

 
The following quick reference cheatsheet guide will provide you with the basic SQL commands needed to start querying and modifying tables. It will show you how to access data from a database, how to filter this data, how to perform joins, and even how to make modest table modifications. This is not meant to be an exhaustive list of SQL functionality, but rather a starting point. Once you master this subset of commands, you should be set to take on some more challenging operations.

Take it from us: learning SQL won't be in vain. There is zero chance it will go out of style in the next few years, and can be immediately of practical use in your learning and your career. Get the cheatsheet now and get started.