Which term defines the rules enforced on data to maintain integrity?

Which term defines the rules enforced on data to maintain integrity?

• A. Schema
• B. Constraints
• C. Fields/columns
• D. Tables

Answer: (B)

Constraints define the rules enforced on data to maintain integrity. In a relational database, these rules govern what values are allowed and how data relates across tables, ensuring accuracy and consistency. Examples include NOT NULL, UNIQUE, CHECK, and FOREIGN KEY, which the database management system enforces automatically when data is inserted or updated. Schema is the overall design of the database—the blueprint that describes tables, columns, and data types. Fields or columns are the individual data attributes stored in a table. Tables are the collections of rows. While these describe structure and storage, they don’t by themselves enforce the data integrity rules that constraints provide.

Constraints define the rules enforced on data to maintain integrity. In a relational database, these rules govern what values are allowed and how data relates across tables, ensuring accuracy and consistency. Examples include NOT NULL, UNIQUE, CHECK, and FOREIGN KEY, which the database management system enforces automatically when data is inserted or updated.

Schema is the overall design of the database—the blueprint that describes tables, columns, and data types. Fields or columns are the individual data attributes stored in a table. Tables are the collections of rows. While these describe structure and storage, they don’t by themselves enforce the data integrity rules that constraints provide.