SQL and Business Logic
Business logic is supposed to be the part of the application where you
deal with customer or user facing decisions and computations. It is often
argued that this part should be well separated from the rest of the
technical infrastructure of your code. Of course, SQL and relational
database design is meant to support your business cases (or user stories),
so then we can ask ourselves if SQL should be part of your business logic
implementation. Or actually, how much of your business logic should be SQL?