Before taking the beginner's course, I first completed the intermediate course because this course was recommended to me. People around me told me that I would be using subqueries a lot, so I decided to take the advanced course as well. I will definitely take the beginner's course before taking the advanced course. If I get the chance, I would also like to receive a cheat sheet. I think it will be a great help since I am currently working while searching with multiple windows open. I will leave an email at bling_it_on@naver.com! Thank you so much for the great course!