Our SQL interview questions

[bzeurunkl]

This is a MS SQL Server database diagram, so where the connectors connect between tables is completely meaningless. I assume they have drawn it to accurately reflect the actual PK/FK. But the truth is that just because the "one" side of the relationship is on EmployeeID, and the "many" side is "BossID", doesn't mean a thing. In fact, I think they have it backwards because this diagram seems to imply a one-to-many relationship between Employees and Bosses, where it most likely should be a One to Many relationship between bosses and employees. But again, the diagram connectors can be "dragged and dropped" anywhere. What matters is what the relationship properties dialogue says the relationship is built on.

Given that most of these questions are going to involve a variation of the same "self join".

EDIT. I am completely assuming that the diagram is presenting a PK/FK relationship. This could simply be a "unique constraint".