How to enforce the uniqueness of a relationship?
We went through an HR-Application workshop/exercise and watch several videos about VB.
In that workshop we worked with three Business objects: (Location, Department and Employee).
I wonder, how can we enforce the uniqueness of a relationship?
For example, how can we implement that a department has one to one relationship to a location?
The same applies to the employee-department relationship, an employee can only be a member in one department.