How should app data be stored in a database?

Question

If I have an app that has foundational values that can be changed, like categories and a service fee, how do I store these in a database? For example, let's say that a service fee of 5% applies to User 1 who is located in Seattle, WA and a fee of 7% should apply to User 2 located in Manhattan, NY.

Right now I have an admin panel that can set the service fee, but it would be across the entire app since it stores this value in a MongoDB database along with other app "settings".

Is storing a value like this (or product categories) in a database the proper way to do this, and I simply check the user location when they use the app to determine the correct service fee/categories, or should I be taking another approach?

Answer 1

While the values themselves for any given fee might change for each user, presumably they're all the same sets of fees across everyone. In an effort not to over-engineer a solution, I'd just create a table in which you assign an ID and have a decimal column for each of your various fees. In your user table create a foreign reference to the ID of the fees assigned to any given user.