Aaron Francis made some very cool MySQL videos for PlanetScale before he was let go: <a href="https://www.youtube.com/playlist?list=PLQiYtJSQdSEDH7TCBxm6tgdTc8rbKoX6K" rel="nofollow">https://www.youtube.com/playlist?list=PLQiYtJSQdSEDH7TCBxm6t...</a>