SQL for Data Science (Notes)
Chapter-by-chapter notes on a six-hour MySQL course: why databases exist, how they're designed (keys, integrity, ER diagrams), and how to write SQL. Every chapter ends with conceptual questions that test why, and several have a live SQL engine you can run in the browser.
Source: Complete SQL Course For Data Science | SQL For Data Science in 6 Hrs by Nitish Singh, CampusX. These are my personal, unofficial study notes; the teaching is his, so watch the video for the definitive treatment. All 12 chapters are covered, plus interview practice sessions.
Chapters
Practice sessions
Interview-style problems from CampusX's live classes, solved with runnable editors. Do these after the chapters.
How to use these notes
Watch, then read
Each chapter links to its exact timestamp in the video.
Do the quizzes
Conceptual questions at the end of each chapter check that you understand why.
Run the SQL
Most chapters have runnable code blocks and a SQL lab (a real SQL engine in your browser).
Track progress
Tick "mark as done" at the end of a chapter; it's saved in your browser.