Question

I’m designing a database for a franchiser. My skill level is intermediate at best (I just work in the franchiser’s office). This database must define store locations and franchisees. So I know I will need a “store” table and a “franchisee” table. The “store number” will be the primary key in the store table. One franchisee can own multiple stores. I figured I could just assign a “Franchisee ID” as a primary key in the franchisee table to like franchisees to stores. Here’s my issue: Each store can be owned by up to 4 franchisees. So I’m stuck on how to define all that. I’m not sure I can do multiple franchisee ID’s and even if I could, often, stores are only owned by 1 or 2 people. That means many blank fields. Also, I’m unsure of how it will all come together when I need to pull queries. Any suggestions on the most logical way to do this?

Answer 1

Okay, so for the stores, you same to have a valid primary key already – the StoreNumber. So you “Store” table will be something like

Store     StoreNumber INTEGER   PRIMARY KEY
          StoreName   STRING 
          ......

Then you have another table Franchisee which will hold the franchisees and their info – primary key will be the FranchiseeID

Franchisee  FranchiseeID    INTEGER  PRIMARY KEY
            FranchiseeName  STRING
            (other fields)

To join those two, since you can have more than a single owner, you need a StoreOwner table, something like this:

StoreOwner    StoreNumber    INTEGER  FOREIGN KEY to "Store"
              FranchiseeID   INTEGER  FOREIGN KEY to "Franchisee"

The combination of both fields (StoreNumber, FranchiseeID) will be your primary key in StoreOwner.

That way, you can have any number of owners for a given store.