How it works
Each lesson is a short read with real queries and what they return, then practice questions. Most have you write a query: it runs as you type on a small shop database in your browser (SQLite), shows what it returns, and is marked right as soon as it returns the same rows as the answer. Any query that gets there counts, so there’s more than one right way. Some questions practise one idea and ask you to use it, like a JOIN or a window function. You can try again as often as you like; “Show the result to aim for” shows the rows you’re after, and after two misses there’s a button to show a query that works.
What do I need to know first?
Nothing. It starts from zero. The queries run on SQLite in this page; what you learn works in PostgreSQL, MySQL, SQL Server and the data warehouses, and the lessons point out where they differ.
The other AI and data engineering courses
- AI: How LLMs work: 7 lessons
- AI: Retrieval and RAG: 7 lessons
- AI: Agents and workflows: 7 lessons
- Data engineering: Warehouses and pipelines: 7 lessons
- Finance: Loans and real estate: 7 lessons
Where is my progress saved? In this browser, like the rest of the site. Nothing to sign up for.