[throwaway23597]

IMO there's a big difference between university level SQL and the ability to competently write SQL in a professional setting. In university, at least at my school, you are getting maybe at most 3 tables overall, with 3-5 columns each. Professionally, you're dealing with hundreds, maybe thousands of tables, each with between 10-1000 columns, and usually not even in 1NF either. It really takes a lot of practice writing queries professionally to get to a level of competence here.