Question

4 Consider the following relational schema, DDL statements and tables:

EMPLOYEE( EmployeeID, EmployeeName, SupervisorID, DepartmentID)

PROJECT (ProjectID, EmployeeID)

DEPARTMENT( Department ID, DepartmentName)

CREATE TABLE EMPLOYEE

( EmployeeID          INT           PRIMARY KEY,

   EmployeeName   VARCHAR(50)      NOT NULL,

   SupervisorID INT DEFAULT 9,

   DepartmentID   INT,

   FOREIGN KEY (SupervisorID) REFERENCES EMPLOYEE (EmployeeID)

   ON DELETE SET DEFAULT   ),

   FOREIGN KEY (DepartmentID) REFERENCES DEPARTMENT(DepartmentID)

   ON UPDATE SET NULL);

CREATE TABLE PROJECT (

ProjectID    INT          PRIMARY KEY,

EmployeeID INT DEFAULT 9,

FOREIGN KEY (EmployeeID) REFERENCES EMPLOYEE (EmployeeID)

ON UPDATE CASCADE);

CREATE TABLE DEPARTMENT(

DepartmentID INT PRIMARY KEY,

DepartmentName   VARCHAR(50),

);

EMPLOYEE

EmployeeID	EmployeeName	SupervisorID	DepartmentID
6	A	7	6
7	B	7	6
1	C	8	7
8	D	9	3
9	E	NULL	6

PROJECT

ProjectID	EmployeeID
1	6
2	7
3	1
4	8
5	7
6	1

DEPARTMENT

DepartmentID	DepartmentName
3	X
6	Y
7	Z

Show the status of the above tables after each of the following operations:

a. Updating the EmployeeID from 1 to 11. If it is rejected, explain.

b. Insert a new project with ProjectID= 23 and EmployeeID= 17. If it is rejected, explain.

c. Deleting the employee whose ID= 8. If it is rejected, explain.

d. Changing the employee whose ID= 8 to 13.

Answer 1

a oplatete Employeelo Fom thal osethe pRogec table modie o PROJECT table Cascade ow dpdad So

De che aree table.

íorpie and Finall the