Problem 3. We want to construct a database for a world-wide package delivery company (e.g., DHL). The database must be able to keep track of customers who ship items and customers who receive items (some customers may do both). For each customer, the database needs to store the customer ID, name and address. Each package must be trackable, so the database must store the locations through which the package has gone. For each location, the database needs to store the location ID, the city name and the country name. For each package, the database must store the package ID and the weight.
(a) Draw an E-R diagram that reflects the above reuirements.
(b) Define a set of relational schemas and identify primary and foreign keys. Try not to include redundant schemas.