I am designing a database prototype for my senior design class, and there are is a problem that I don't have any idea about where to even start. So, anybody out there, I will highly appreciate if you can take some of your precious time to help me out.
Consider I have a list box with three attributes (State, Region, and City) of an entity called Country. I should be able to select one or more than one of these attributes and there values should show up in another list box. These values may be repeated, but I only want unique values in the list box. For example for State there might be two entries: New York and New York, but I only want to see one entry in the second list box. Again, I should be able to select one or more than one of these values from the second list box and the corresponding country name should show up in the third list box. For example if I select New York and California from the second list box, than the corresponding country names which are stored in the table "Country" should show up in the third list box.
I look forward for some help.
Thank you