Local Walmart store is upgrading its legacy database system. The new database system will be used to manage the supple chain and transactional data, including products, vendors, customers and invoices. Design a relational database model for this system. Some of the business rules are as follows: a product can have many vendors, and a vendor can supply many products. A customer can have many invoices, and each invoice is associated with only one customer. Each invoice may contain many different products, and a product can appear on many invoices (For example, a TV model can be purchased by many customers and therefore appears on multiple invoices).
A. Start with drawing the Entity-Relationship Model. List all entities, attributes, and relationships among entities.
B. Draw the relational model.