Question

In a table regarding the entries of students, which among these can be the most appropriate for PRIMARY KEY?

• A. RollNumber
• B. Name
• C. DateofBirth
• D. Age

Hint:

A Primary Key must be unique and NOT NULL.
In exams, look for formal, system-assigned identifiers (e.g., RollNumber, EmployeeID, AadhaarNumber) over natural characteristics (e.g., Name, Age, Date of Birth).

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
A Primary Key must be unique for every record and cannot contain NULL values.

Step 2: Detailed Explanation:
1. RollNumber: Is unique for each student and is typically assigned specifically for identification.
2. Name: Multiple students can have the same name.
3. DateofBirth: Multiple students can share the same birth date.
4. Age: Many students will share the same age.

Step 3: Final Answer:
RollNumber is the most appropriate choice for a Primary Key.