Using the NorthWind database:

1. Find the employees that have created no purchases (using a set operation)
2. Find the employees that have created no purchases (not using a set operation)
3. Find the orders placed by a custormer in Austria or in Venezuela (using a set operation)
4. Find the orders placed by a custormer in Austria or in Venezuela (not using a set operation)
5. Compute the total number of items (quantity) to be shipped to Italy.
6. Compute the cities that have a customer and are the destination of a shipment.
7. Compute the cities that have a customer or are the destination of a shipment.
8. Compute the cities that are the destination of a shipment but have no customer.