The Postgres docs are some of the best reading you can do. Super digestible, great examples, and all around excellent for learning.

"Become a Select St*r!" (https://wizardzines.com/zines/sql/)

Once you have a basic understanding of SQL, I found it really informative to go closer to the source, e.g. C. J. Date and Hugh Darwen's "A Guide to the SQL Standard", or perhaps other books by them.

There's a lot of incomplete and misunderstood information floating around in blog tutorials or potboiler textbooks.

I found reading the postgres documentation and playing around with each of the examples useful.

I highly recommend SQL for Smarties.

https://www.amazon.com/Joe-Celkos-SQL-Smarties-Programming/d...