Consider the following relational schema:

employee(empId,empName,empDept)

customer(custId,custName,salesRepId,rating)

salesRepId is a foreign key referring to empId of the employee relation. Assume that each

employee makes a sale to at least one customer. What does the following query return?

SELECT empName FROM employee E

WHERE NOT EXISTS (SELECT custId FROM customer C WHERE C.salesRepId = E.empId

AND C.rating <> ’GOOD’);