I'm a application developer using django, since most of the stuff learn happens behind Django'ORM.<p>So i'm looking to learn relational database, so that i can design better database system.<p>Can anybody guide what approach should be taken ?
My favorite introductory book is <i>Database Systems: The Complete Book</i>, 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.<p>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.<p>Good luck.
You can get started using <a href="https://pgexercises.com/" rel="nofollow">https://pgexercises.com/</a> , which focus on Postgres