Question

Entity integrity constraint states that no ______ key value can be null because it is used to identify individual tuple in a relation.

• A. Secondary
• B. Primary
• C. Partial
• D. Particular

Answer 1

The correct option is B Primary

Entity integrity constraint is one of the constraints on relational database. It states that no primary key value can be null because it is used to identify individual tuple in a relation. Null value implies that we cannot identify such tuples or identify these as alike. A failure to distinguish them means they are duplicates.