It was nice to be able to solve problems about JOIN, which I was not familiar with. In particular, I was able to learn how to aggregate data meaningfully, like pivoting, so I am glad I took this course. It seems that the advanced class includes conceptual gaps in using SQL in the workplace (how to read ERD, subqueries, WINDOW FUNCTIONS, etc.), so I think I will follow the next class. It was a great help in learning SQL!