12. For the given database STUDENT-PROJECT, answer the following:
(a) Name primary key of each table.
(b) Find foreign key(s) in table PROJECT-ASSIGNED.

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

Ans:
(a)

Table	Primary key
Student	Registration_ID
Project	ProjectNo
Project_assigned	–

(b) Registration_ID and ProjectNo
(c) Yes, RollNo can be alternate key in table STUDENT because RollNo can not have Null value and always be Unique.
(d) Yes, RollNo can be assigned duplicate values as it is not a primary key.