Encapsulation can be a wonderful thing. I'd have to say that generally in an n-tier architecture it is common practice to place business rules and logic in the middle tier, NOT the database (in the form of sprocs). However, each situation is different. If all you're doing is a few updates, a delete, and then a select then all that happens on the database server anyway - why introduce a middle tier that will just add more database calls? It is often said that in order to achieve flexibility one of the most common trade-offs is performance. You need to decide how much flexibility you need. Only then can you decide what to do in classes (VB.NET or C#), what to do in sprocs, and what to do in the UI.