Review my introduction to SQL for Excel users Tutorial
roundsquare: A few thoughts.1) I like the visualization.  Its a key part of understanding SQL.2) However, I don't see this as taking advantage of a user's excel knowledge.  Why not make an analogy they will understand?  Join is similar to vlookup!  Try to do something in excel first and then do it SQL.  That will be tough for advanced SQL, but should be (sort of) doable early on.  So far, someone with advanced knowledge of excel wouldn't be much better off than someone just getting started.3) Someone might ask the question: "Why have the from clause?  Why not always do "select person.first_name where....?"  I don't know how your will answer this...4) In your explanation of having the same column name in two places, why not use email address?  People have email addresses as well as companies.  You mention a customer table but the student can't see one, so it could be confusing.I think there is the possibility of doing some great stuff with the excel SQL analogy...As for future topics: Keep in mind what you can do with excel and go from there.  Sums, products, etc... can all be done.  Inserts are tougher to explain, I'd keep it for later when you have people thinking in SQL and not excel.