SQL

Articles

• 10 Easy Steps to a Complete Understanding of SQL - Lukas Eder

• Best practices for writing SQL queries - Metabase

• Creating Histograms in SQL - PopSQL

• Improve your SQL skills X2 in 5 minutes - Anton Zaides

• SQL Cheat Sheet - Anton Zhiyanov

• SQL join flavors - Anton Zhiyanov

Books

• Use The Index, Luke! - A Guide to Database Performance for Developers - Markus Winand

GitHub Repositories

• SQL tips and tricks

Playgrounds

• SQL OnLine IDE

• SQL Playground

Tools

• Harlequin - the SQL IDE for your terminal

Websites

• Advent of SQL

• Human to SQL Translator

• Lost at SQL - SQL learning game

• Select Star SQL

• SQL for Devs

• SQLBolt

• SQLZOO

• The Querynomicon - An Introduction to SQL for Weary Data Scientists