Database Fundamentals — Question 77

This question requires that you evaluate the underlined text to determine if it is correct.
A relational database management system employs the concept of an attribute to ensure that data entered into a field in a column is valid.
Instructions: Review the underlined text. If it makes the statement correct, select "No change is needed." If the statement is incorrect, select the answer choice that makes the statement correct.

Answer options

• A. No change is needed
• B. a primary key
• C. a constraint
• D. an index

Correct answer: C

Explanation

The statement is incorrect because it does not accurately reflect how validity is enforced in a relational database. A 'constraint' is used to ensure that the data entered into a field adheres to specified rules, making option C the correct choice. The other options do not serve this purpose; a primary key is used for unique identification, an index is for optimizing queries, and 'No change is needed' is incorrect.