I've been an engineer for last 12 years and during my career I've been mentoring people and helping them learn SQL. I used different approaches but did not find any better approach from learning by [doing] writing SQL queries and solving tasks. Even if it was by leveraging the AdventureWorks database, and/or a real world production database.

So my question to people who just entering into any developer role and/or learning just SQL....

How do you learn SQL now, and what is the best approach for you personally?