I can definitely say that this is one of the best SQL data analysis lectures. I highly recommend this to those who have learned basic SQL grammar but want to improve their vague SQL skills through various practical cases. Thanks to the instructor's excellent teaching skills and very informative lecture content, I feel like I have newly discovered SQL, and if you listen to the lecture and practice consistently, your skills will definitely improve. This is a high-quality lecture. It was also doubly good because he kindly answered my questions during the lecture. I really recommend it. Thank you.