So I’m working on a new project, for a new employer. The database that I have is lacking a lot of referential integrity. Now, the down side is that because I didn’t originally design this database, I have to be careful as it’s possible that it was designed NOT to have this integrity for a purpose. Really the only way to determine this is to ask the original developer, but if you don’t have access to the original developer, ask the business. They might know. They just might surprise you!