Given the basic E R diagram and relational model, which of the the following is incorrect?

1. AAn attribute of an entity can have more than one value
2. BAn attribute of an entity can be composite
3. CIn a row of relational table, an attribute can have more than one value
4. DIn a row of a relational table, an attribute can have exactly one value or a NULL value

Pick an option to check yourself, or open the answer below.

Show answer & explanation

Correct answer: C. In a row of relational table, an attribute can have more than one value

Explanation

In ER models attributes can be multivalued or composite. In a relational table every attribute value must be atomic — one value or NULL — so C is incorrect.