1. Write an SQL command that will find any customers who have not placed orders.
2. Find the employees who supervise other employees. List their names and phone number as well as the number of employees they supervise (label this value DepartmentCount). List only those supervisors who supervise fewer than two employees.
3. A. List the name of each employee, his or her birth date, the name of his or her manager, and the manager’s birth date. Give appropriate aliases.
B. Now modify the query to report only those employees who are older than their manager;
4. For every order calculate the total dollar amount owed on that order (you’ll have to calculate this total from attributes in one or more tables; label this result Order_Due). Then calculate the amount received in payments on that order; label this Order_Paid, and finally calculate the difference of the amounts.
A. To make this query a little simpler, you don’t have to include those orders for which no payment has yet been received. List the results in decreasing order of the difference between total due and amount paid
B. Now modify the above query to also include those orders for which no payment has yet been received. List again the results in decreasing order of the difference between order due and amount paid.