You are designing a database for an e-commerce business that sells athletic shoes online. Your business purchases shoes wholesale from major manufacturers like Nike and Adidas and resells them to consumers. Your target market consists of long-distance runners who do 5K and 10K races and marathons. Through your website, you specialize in helping each runner find the best shoe for his or her individual performance level and running style. What entities would a database for this business need to include? What are some business rules that would apply to these entities, and how would they be reflected in the database design?