Question

Explain the concept of candidate key with the help of an appropriate example.

Answer 1

The candidate key is a column or set of columns that can help in identifying records uniquely. 

Example, consider a Table STUDENT.

AdmnNo	Roll No	Name	Class	Marks
2715	1	Ram	12	90
2716	2	Ajay	11	98
2811	3	Jayesh	12	98
2914	4	Tarun	11	94

Here, AdmnNo & Roll No define Table uniquely. 

Hence, they are candidate keys