Ask HN: How to learn relational database

My favorite introductory book is Database Systems: The Complete Book, by Hector Garcia-Molina, Jeff Ullman, and Jennifer Widom. The first edition is probably good enough and usable used copies are often available for less than $10 online.

In terms of interacting with relational databases directly, I've found SQLite's command line interface [the command sqlite3] very lightweight. A potential bonus of 'sqlite3' is running it against SQLite databases for applications already on your machine...be careful though.

Good luck.

You can get started using https://pgexercises.com/ , which focus on Postgres

One more thing , what could be the important concepts which should be covered ?