2). (10 points) Suppose that each of the following Update operations is applied directly to the database state shown below. Discuss all integrity constraints violated by each operation, if any.

a). Insert into EMPLOYEE.

b). Delete the WORKS_ON tuples with Essn = 123456789.

c). Modify the SUPERSSN attribute of the EMPLOYEE tuple with SSN= '999887777' to '943775543'.

d). Insert into DEPARTMENT.

e). Delete the EMPLOYEE tuple with Ssn = 987654321.

Answer the question by checking the corresponding cell in the following table.

	Domain violation	Key violation	Entity integrity violation	Referential integrity violation
2a.
2b.
2c.
2d
2e