[neovintage]

I would start with the Mode Analytics SQL tutorial. It's fairly robust and gets into advanced topics: https://community.modeanalytics.com/sql/tutorial/introductio...

That will get you pretty far but the advanced SQL topics will require the study of what the underlying database provides and how it works. Every database is different in terms of how it implements advanced features, if at all. For example, MySQL doesn't have window functions. For postgres related topics, the documentation is excellent, postgresguide.com gives a high level overview, or you can follow craig's blog (http://www.craigkerstiens.com/) that provides a gentle introduction to many of these topics as well.

[craigkerstiens]

Thanks for the mention, I also have an article that walks through not what I'd call advanced but it's at least intermediate SQL here as well - https://www.citusdata.com/blog/2016/09/12/fun-with-sql-compu...

Whenever I do come across blogs that have good articles we aim to feature them in Postgres Weekly, so if you want a regular stream of that type of content it's worth checking out - http://www.postgresweekly.com

[Dowwie]

The Postgres Weekly newsletter is a really valuable service. You not only aggregate information but filter for quality. Thank you for providing this! I've said this before but it warrants re-mentioning :)