Chapter 2 Data Modeling
Chapter 2: Data Modeling
Multiple Choice
1. The Entity-Relationship (E-R) model is .
a. a diagramming technique that describes record structures (i.e. the fields that make
up the records of a file)
b. an alternative to indexing and hashing as a means for providing direct access in
files
c. a diagramming technique that describes entities, their attributes, and the
relationships between them
d. an alternative to file design in which attributes are used instead of fields
e. a diagramming technique that relates entities to each other, attributes to each
other, and relationships to each other
Ans: c
Response: See page 20
2. An association between entities is a(n) .
a. entity type
b. entity occurence
c. record
d. attribute
e. relationship
Ans: e
Response: See page 20
3. A binary relationship is a relationship between two .
a. entity types
b. attribute types
c. associations
d. files
e. cardinalities
Ans: a
Response: See page 20
4. The term “binary” in binary relationship indicates that the relationship is between
a. two halves of an entity type
, Chapter 2 Data Modeling
b. two entity types
c. two divisions of an entity’s attributes
d. two attributes
e. two relationships
Ans: b
Response: See page 20
5. The cardinality of a relationship is .
a. The minimum number of entities that can be involved in the relationship.
b. The maximum number of entities that can be involved in the relationship.
c. The minimum number of attributes that can be in the entity types in a relationship.
d. The maximum number of attributes that can be in the entity types in a
relationship.
e. The minimum number of associations that can be involved in the relationship.
Ans: b
Response: See page 23
6. The modality of a relationship is .
a. The minimum number of entities that can be involved in the relationship.
b. The maximum number of entities that can be involved in the relationship.
c. The minimum number of attributes that can be in the entity types in a relationship.
d. The maximum number of attributes that can be in the entity types in a
relationship.
e. The minimum number of associations that can be involved in the relationship.
Ans: a
Response: See page 24
7. A one-to-one binary relationship .
a. involves a single entity type
b. involves two entity types
c. allows an occurrence of one entity type to be associated with several occurrences
of another entity type
d. allows an occurrence of one entity type to be associated with several occurrences
of another entity type and vice versa
e. restricts the number of attributes that an entity has
Ans: b
Response: See page 23
Chapter 2: Data Modeling
Multiple Choice
1. The Entity-Relationship (E-R) model is .
a. a diagramming technique that describes record structures (i.e. the fields that make
up the records of a file)
b. an alternative to indexing and hashing as a means for providing direct access in
files
c. a diagramming technique that describes entities, their attributes, and the
relationships between them
d. an alternative to file design in which attributes are used instead of fields
e. a diagramming technique that relates entities to each other, attributes to each
other, and relationships to each other
Ans: c
Response: See page 20
2. An association between entities is a(n) .
a. entity type
b. entity occurence
c. record
d. attribute
e. relationship
Ans: e
Response: See page 20
3. A binary relationship is a relationship between two .
a. entity types
b. attribute types
c. associations
d. files
e. cardinalities
Ans: a
Response: See page 20
4. The term “binary” in binary relationship indicates that the relationship is between
a. two halves of an entity type
, Chapter 2 Data Modeling
b. two entity types
c. two divisions of an entity’s attributes
d. two attributes
e. two relationships
Ans: b
Response: See page 20
5. The cardinality of a relationship is .
a. The minimum number of entities that can be involved in the relationship.
b. The maximum number of entities that can be involved in the relationship.
c. The minimum number of attributes that can be in the entity types in a relationship.
d. The maximum number of attributes that can be in the entity types in a
relationship.
e. The minimum number of associations that can be involved in the relationship.
Ans: b
Response: See page 23
6. The modality of a relationship is .
a. The minimum number of entities that can be involved in the relationship.
b. The maximum number of entities that can be involved in the relationship.
c. The minimum number of attributes that can be in the entity types in a relationship.
d. The maximum number of attributes that can be in the entity types in a
relationship.
e. The minimum number of associations that can be involved in the relationship.
Ans: a
Response: See page 24
7. A one-to-one binary relationship .
a. involves a single entity type
b. involves two entity types
c. allows an occurrence of one entity type to be associated with several occurrences
of another entity type
d. allows an occurrence of one entity type to be associated with several occurrences
of another entity type and vice versa
e. restricts the number of attributes that an entity has
Ans: b
Response: See page 23
