С WTF'а. Коллеги оценят вторую реплику.
Mark: I'm a bit puzzled why the first line of the address for each customer is the primary key in the Customer's Table…
Developer: I decided that was the most unique item for each entity.
Mark: So what happens when you get a customer that shares the same first line of the address?
Developer: That generates an error — the user then rings me up and I generate the customer record.
Mark: Ah — so you change the first line of the address, what to?
Developer: Well, I prefix the line with a numerical value — indicating the duplication number.
Mark: So… a new customer with the address of "1 Main Street" would be changed to "2 1 Main Street"?
Owner: Does it?
Developer: Er… Yes.
Owner: Well, that explains why most of our marketing and billing post is never delivered…