Hi, just had few design questions about a database im working on.

1. The coffee and tea tables both have product_upc as a primary key, but this seems to be a problem when trying to use them both as a foreign key for inventory.

2. I was wondering if there are going to be possibly thousands of users per group, around 10 stores per group and around 300 inventory entries per store if i should make a seperate db for each group. The reason in had them in one db was because i wanted to keep the detailed product info together so it would be easy to update.

You've got your cardinalities wrong, but your design seems Ok to me. To give you a hint, the Inventory is actually the parent in a decomposition into coffee and tea.

-PatP

Alright so then would these cardinalities be right?

What im trying to describe in the diagram is a price reporting system. Where each group represents a different geographic location and Where Inventory is a collection of all the prices and corresponding product_upc's, user_id's, and store_id's reported from every store in every region.

So there may be thousands of coffee and tea entries with only a hundred associated with the inventory table because not all will have prices reported by a user. And there may be multiple of each product in inventory because it could be reported at more than one store.