This is not a real-time lecture, but a recorded lecture, so it is not an intentional explanation with errors in the flow, and I wonder if it is possible to edit out parts where errors occur due to mistakes in the process. When I am writing a query during practice and cannot remember the command, I wonder if it is necessary to include all the parts where I get an error and say, "Why is this happening?" in the lecture video. There are many parts where I have to correct typos in the data and take up a lot of time, which breaks the flow of the lecture. Even if you look at the lecture content, the lecture progress is not very smooth. There are also many regrettable points in other classes.