SQL
Query and shape data with standard SQL — running on a real database in your browser.
SQL
SQL is the language of data. It's declarative — you describe what you want and the database figures out how to get it — and it's remarkably durable: the core you learn here has been stable for decades and works, with small variations, across every major database.
How this track works
- Core (Beginner → Advanced): the ~90% of SQL that's identical everywhere. Every example and exercise runs on a real SQLite database compiled to your browser — no setup, no server. Click Run, edit, and try again.
- Dialect appendices: short references for where specific engines
(PostgreSQL, SQLite, SQL Server) diverge from the core —
LIMITvsTOP, identity columns, quoting, and so on.
Work through the core in order; dip into an appendix when you target that engine.
Finished reading? Mark it complete to track your progress.