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 quer

Question

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');

Accepted Answer

Names of all the employees with all their customers having a 'GOOD' rating.. The query checks for employees who do not have any customers with a rating other than 'GOOD'. Therefore, it returns the names of employees whose customers all have a 'GOOD' rating.

Solution

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