Introducing YeSQL: Practical PostgreSQL, One Concept at a Time

I'm happy to share something new: YeSQL is live, a free set of 24 short PostgreSQL lessons — one concept, one runnable query, real data, no signup. It's free to use today, and it's also a prototype for something I've wanted to build for a while: making every query in The Art of PostgreSQL runnable, right on the page.