• Just because you CAN trick SQL Server into allowing a computed column to indirectly reference columns in other tables does not mean you should. My strong suspicion is that if you need to do this then the basic database design is inadequate to meet the business and performance requirements.

    Similarly, I get very suspicious of people embedding business logic in databases. I am not saying it should never be done, but you need to ask yourself several times if it really is the best place for it. A closed 'stove-pipe' application may warrant it, but as data becomes more general in its use, locking a database to the specific functionality of one part of the business restricts its usefulness to the rest of the organisation.