Consider your school's registration database that enforces the following integrity constraint: to enroll in a given class, the student must have completed or currently be enrolled in the listed prerequisite (if any).
Your school, in fact, probably does have that integrity constraint in place. How can you get around that integrity constraint and enroll in a class for which you are not taking nor have completed the prerequisite?
Is this an instance of when you should be able to override an integrity constraint? What are the downsides to being able to do so?