更新和显示MySQL数据库的评级

For practice, I'm creating a website that shows the ratings of professors. I'm confused about how to approach this though. Since the rating can change and is made up of reviews from students, where do I put this information? Does my professor have a "rating" column in his table? Or do I have a table for reviews, and when I display rating on the professor's page, it has to calculate the rating from all the reviews first?For practice, I'm creating a website that shows