Here's the Scenario
Your newly created web service is exactly what your boss asked you to craft. It creates a new user record in the Users table, and inserts records into three different tables after doing a bit of gnarly math on some numbers. Now it's demo time. The ASP.NET front end that you have running to test the web service is simple, yet functional. Your boss likes it, and tries out numbers for various business scenarios that the sales staff will encounter. But when he eventually mistypes and enters 6 instead of 6, the web service throws an exception midway through the process, and the tables lose the required referential integrity. Your boss looks mad!