1. There was a lot of coughing during the lecture. I hope you pay more attention to your health, such as coughing. Don't you think that students prioritize their health over your lecture? 2. I felt that the explanation was too roundabout and loose. For example, if the = of the where clause returns more than two results, the single row subquery returned more than two rows. I wish you had pointed out the error accurately, but you said that it would be better to use the in clause. 3. Since it is a modeling lecture, I hope you make the criteria for naming tables and determining columns more clear, and that it is a lecture that allows you to think about more complex situations that are used in practice. For example, it is clearly a DB table, but 't_' is added for no reason, or it is a college student's academic management system, but key information is included (does a key really need to be included when it is college student information) If the instructor's criteria for determining the table name were clear, I think the listeners would have thought, "Oh, this instructor made this choice based on this criteria." 4. If it is database modeling, why do we need to do modeling, why do we set these columns in practice instead of "This is how it is in practice," and if we had a detailed explanation of the column size based on A and the column type based on B, and what service and environment it is modeling for, it would have given the students more room to think about problem solving, so I hoped for more skill improvement. - Still, I listened carefully, thinking that I was learning a major class again, since it was taught from a beginner's perspective on database modeling. - It was also good that you taught us the solution approach when solving SQL problems. - I also enjoyed learning about the commerce domain examples. Thank you for the great lecture.