Question

Student Project Database
Table: STUDENT
Roll No	Name	Class	Section	Registration_ID
11	Mohan	XI	1	IP-101-15
12	Sohan	XI	2	IP-104-15
21	John	XII	1	CS-103-14
22	Meena	XII	2	CS-101-14
23	Juhi	XII	2	CS-101-10
Table: PROJECT
ProjectNo	PName	SubmissionDate
101	Airline Database	12/01/2018
102	Library Database	12/01/2018
103	Employee Database	15/01/2018
104	Student Database	12/01/2018
105	Inventory Database	15/01/2018
106	Railway Database	15/01/2018
PROJECT ASSIGNED
Registration_ID	ProjectNo
IP-101-15	101
IP-104-15	103
CS-103-14	102
CS-101-14	105
CS-101-10	104

 

For the above-given database STUDENT-PROJECT, answer the following:

1. Name the primary key of each table.
2. Find foreign key(s) in table PROJECT-ASSIGNED.
3. Is there any alternate key in table STUDENT? Give justification for your answer.
4. Can a user assign duplicate value to the field RollNo of STUDENT table? Justify.

Answer 1

1. The primary key of Table STUDENT: Roll No.
   The primary key of Table PROJECT: Project No.
   The primary key of Table PROJECT ASSIGNED: Registration_ID.
2. Foreign key in table PROJECT ASSIGNED: ProjectNo.
3. Yes, the Name is the alternate key in table STUDENT. In this table, Roll No. and Name is the candidate key in which Roll No. is selected as the primary key then the remaining key (Name) is an alternate key.
4. No, a user cannot assign duplicate value to the field RollNo, of the STUDENT table because Roll No. is the primary key and the primary key uniquely identifies each record in a table.