SQL is the lingua franca of data. From a 12-row product catalogue on a side-project to a 50-billion-row event log at a tech giant, the language you ask questions in is the same: SELECT ... FROM ... WHERE ... GROUP BY. This tutorial takes you from "what is a table?" to window functions and transactions - the same path a working data analyst, backend developer, or SRE walks through in their first six months on the job.
We start with installing a free SQL engine and connecting it to VS Code (on Ubuntu, see install VS Code on Ubuntu for the editor install), then walk through every fundamental query - filtering, joining, aggregating, updating, deleting - before moving on to the things that separate confident SQL writers from struggling ones: every JOIN type with side-by-side diagrams, GROUP BY with HAVING, the five aggregate functions, all four major constraint types, window functions, stored procedures, triggers, and transactions. Each lesson is short, every snippet was tested on MySQL 8, PostgreSQL 14, and SQL Server 2019, and the differences between vendors are called out explicitly where they matter.
Click Start the course to begin with Getting started with SQL, or jump to the topic you need - JOINs, GROUP BY, ORDER BY, Aggregates, and Window Functions and CTEs are the chapters working developers and analysts come back to most often. If you finish this course and want to specialize, the next courses are Python Tutorial (for pairing SQL with application code) and the Pandas Tutorial (for moving from SQL into in-memory data analysis).

