An accounts payable system includes information about three entities - supplier, invoice, and inventory. Each supplier or Inventory item is given a unique Supplier# or Item#, respectively. Each invoice is assigned a unique Invoice#. Each invoice includes many inventory items and each inventory item appears on several invoices.
a. Give an example of a many-to-many relationship in the accounts payable system.
b. Draw an E-R diagram representing the two entities with many-to-many relationship. Include entities, relationships and cardinalities
c. Revise the E-R diagram prepared in response to part b by adding a junction table and eliminating the many-to-many relationship.