Which of the following relational database constructs is used to ensure valid values are entered for a column?

Which of the following relational database constructs is used to ensure valid values are entered for a column?
A . Schema
B . Permissions
C . Constraint
D . Column

View Answer

Answer: C

Explanation:

A constraint is a rule or a restriction that is applied to a column or a table in a relational database to ensure that only valid values are entered. Constraints help to maintain the integrity, accuracy, and consistency of the data. For example, a constraint can be used to specify that a column must not contain null values, or that a column must contain unique values, or that a column must match a value in another table12.

Reference: = CompTIA IT Fundamentals (ITF+) Study Guide, 2nd Edition, Chapter 5: Database Fundamentals3; Constraints in Relational Database Model – Online Tutorials Library