This set of Database Multiple Choice Questions & Answers (MCQs) focuses on “The Entity-Relationship Model”.
1. An ________ is a set of entities of the same type that share the same properties, or attributes.
a) Entity set
b) Attribute set
c) Relation set
d) Entity model
Explanation: An entity is a “thing” or “object” in the real world that is distinguishable from all other objects.
2. Entity is a _________
a) Object of relation
b) Present working model
c) Thing in real world
d) Model of relation
Explanation: For example, each person in a university is an entity.
3. The descriptive property possessed by each entity set is _________
Explanation: Possible attributes of the instructor entity set are ID, name, dept name, and salary.
4. The function that an entity plays in a relationship is called that entity’s _____________
Explanation: A relationship is an association among several entities.
5. The attribute name could be structured as an attribute consisting of first name, middle initial, and last name. This type of attribute is called
a) Simple attribute
b) Composite attribute
c) Multivalued attribute
d) Derived attribute
Explanation: Composite attributes can be divided into subparts (that is, other attributes).
6. The attribute AGE is calculated from DATE_OF_BIRTH. The attribute AGE is
a) Single valued
b) Multi valued
Explanation: The value for this type of attribute can be derived from the values of other related attributes or entities.
7. Not applicable condition can be represented in relation entry as
d) Blank Space
Explanation: NULL always represents that the value is not present.
8. Which of the following can be a multivalued attribute?
d) All of the mentioned
Explanation: Name and Date_of_birth cannot hold more than 1 value.
9. Which of the following is a single valued attribute
10. In a relation between the entities the type and condition of the relation should be specified. That is called as______attribute.
Explanation: Consider the entity sets student and section, which participate in a relationship set takes. We may wish to store a descriptive attribute grade with the relationship to record the grade that a student got in the class.
Sanfoundry Global Education & Learning Series – Database Management System.
The Entity-Relationship Model