Hi Brian - awesome video! It really helped me out :) Just a quick question: using your example with King & Melville, if we wanted to create a database off of that data alone, does Book functionally determine Author?
Using that example, book *could* functionally determine author, but remember that while we can rule FDs OUT by looking at the data, we can't rule them IN via the data. We need instead to look to the problem domain and data requirements. What do we plan to do with books with multiple authors? Keeps all authors together in a single attribute? If so, then yes, B --> A. Perhaps we'd want to distinguish between first author and subsequent authors. And how are we treating editions? Authors sometimes change between editions. Do we treat different editions as the same book? If so, then book doesn't determine author if authors change over editions, which they certainly can. And so on... Short answer is you need to find out from the stakeholders/requirements
Hi Brian - thanks for the reply. If possible, could you do a video that follows on from this one? One where you start putting tables into 1NF, 2NF, 3NF? :)
