Database Fundamentals — Question 2

You accept an IT internship at a local charity. The charity wants you to help them with compliance and auditing requirements.
You need to ensure that a column or combination of columns uniquely identifies each row of a table.
Which constraint should you define?

Answer options

• A. Primary key
• B. Secondary key
• C. Foreign key
• D. Default key

Correct answer: A

Explanation

The correct answer is A, Primary key, because it is designed to uniquely identify each record in a table. Options B (Secondary key) and D (Default key) do not serve the purpose of ensuring uniqueness, while C (Foreign key) is used to establish a relationship between two tables rather than ensuring uniqueness within a single table.