The lecture was also very good because it was recently created. There were many helpful parts and a lot of basic content. However, if there was something to be sorry about in the DB part, it was that the lecture started with pure JDBC code and went through the process of modifying it to Spring Data JPA, but when I tried to review only the necessary parts later, I couldn't follow the code unless I reviewed pure JDBC again... Other than that, it was very good.