Good software habits apply to databases too. Trust in these little design tips to build a useful, rot-resistant database schema. It is a universal truth that everything in software eventually rots.

I have an order table that is an order for a customer. I need to reference as a foreign key an unknown number of products that could make up the order (product_id) how do I do this? What am I missing.

Normalization clusters data items together based on functional dependencies within the data items. This normalized arrangement expresses the semantics of the business items being presented.