What's the best practice for primary keys in tables?

Question

When designing tables, I\'ve developed a habit of having one column that is unique and that I make the primary key. This is achieved in three ways depending on requirements

Answer 1

I always use an autonumber or identity field.

I worked for a client who had used SSN as a primary key and then because of HIPAA regulations was forced to change to a "MemberID" and it caused a ton of problems when updating the foreign keys in related tables. Sticking to a consistent standard of an identity column has helped me avoid a similar problem in all of my projects.