The tutorials and interactive learning at SQL Tutorial are pretty good. Not Postgres (well, don't know anything about their implementation). I've been having

The tutorials and interactive learning at SQL Tutorial are pretty good. Not Postgres (well, don't know anything about their implementation). I've been having my kids go through it. They are learning a lot. I would recommend this site to anyone who needs to start with SQL from the ground-up and get a reasonable understanding of the language with practical hands-on usage. https://www.sqltutorial.org/ https://www.sqltutorial.org/ A good first step before jumping into CrunchyData?