CHAPTER 4: ENTITY RELATIONSHIP (ER) MODELING
1. The entity relationship model (ERM) is dependent on the database type.
a. True
b. False
2. The Crow’s Foot notation is less implementation-oriented than the Chen notation.
a. True
b. False
3. An entity in the entity relationship model corresponds to a table in the relational environment.
a. True
b. False
4. In the entity relationship model, a table row corresponds to an entity instance.
a. True
b. False
5. In the Chen and Crow’s Foot notations, an entity is represented with a rectangle containing the entity’s name.
a. True
b. False
6. In the original Chen notation, each attribute is represented by an oval with the attribute name connected to an
entity rectangle with a line.
a. True
b. False
7. Software vendors have adopted the Chen representation because of its compact representation.
a. True
b. False
8. A composite identifier is a primary key composed of more than one attribute.
a. True
b. False
Chapter 4: Entity Relationship (ER) Modeling
9. The Crow’s Foot notation easily identifies multivalued attributes.
a. True
b. False
10. Composite attributes make it easier to facilitate detailed queries.
a. True
b. False
11. Relationships between entities always operate in one direction.
a. True
b. False
12. Connectivities and cardinalities are established by concise statements known as business rules.
a. True
b. False
13. In Chen notation, there is no way to represent cardinality.
a. True
b. False
14. In implementation terms, an entity is existence-dependent if it has a mandatory primary key.
a. True
b. False
15. A weak relationship exists if the primary key of the related entity contains at least one primary key component
of the parent entity.
a. True
b. False
16. In a 1:M relationship, to avoid the possibility of referential integrity errors, the data of the “1” side must be
loaded first.
a. True
b. False
Chapter 4: Entity Relationship (ER) Modeling
17. Unary relationships are common in manufacturing industries.
a. True
b. False
18. Referential integrity and participation are both bidirectional, meaning that they must be addressed in both
directions along a relationship.
a. True
b. False
19. A weak entity has a primary key that is partially or totally derived from the parent entity in the relationship.
a. True
b. False
20. The existence of a mandatory relationship indicates that the minimum cardinality is 0 or 1 for the mandatory
entity.
a. True
b. False
21. To implement a small database, a database designer must know the “1” and the “M” sides of each relationship
and whether the relationships are mandatory or optional.
a. True
b. False
22. The process of database design is a sequential process.
a. True
b. False
23. The entity relationship diagram (ERD) represents the database as viewed by the end user.
a. condensed b. physical
c. logical d. conceptual
24. The notation of entity-relationship modelling can be used for both conceptual and implementation
modelling.
a. Bachman b. UML
c. Chen d. Crow’s Foot
Chapter 4: Entity Relationship (ER) Modeling
25. A(n) is the set of possible values for a given attribute.
a. domain b. range
c. identifier d. key
26. Ideally, an entity identifier is composed of attribute(s).
a. three b. one
c. two d. six
27. A attribute can be further subdivided to yield additional attributes.
a. composite b. simple
c. single-valued d. multivalued
28. A attribute is one that cannot be subdivided.
a. composite b. simple
c. single-valued d. multivalued
29. The conceptual model can handle relationships and multivalued attributes.
a. 1:1 b. M:N
c. 1:M d. 1:N
30. A derived attribute is indicated in the Chen notation by a that connects the attribute and an entity.
a. single line b. dashed line
c. double dashed line d. double line
31. The decision to store attributes in database tables depends on the processing requirements and the
constraints placed on a particular application.
a. multivalued b. derived
c. single-valued d. composite
32. A relationship is an association between .
a. objects b. entities
c. databases d. fields
Chapter 4: Entity Relationship (ER) Modeling
33. expresses the minimum and maximum number of entity occurrences associated with one occurrence of
the related entity.
a. Connectivity b. Relationship
c. Dependence d. Cardinality
34. In the entity relationship diagram (ERD), cardinality is indicated using the notation, where max is the
maximum number of associated entities and min represents the minimum number of associated entities.
a. (max, min) b. (min, max)
c. [min … max] d. {min|max}
35. When the specific cardinalities are not included on the diagram in Crow’s Foot notation, cardinality is implied
by the use of _____.
a. symbols b. attributes
c. images d. tables
36. Knowing the minimum and maximum number of occurrences is very helpful at the application software
level.
a. object b. attribute
c. data d. entity
37. An entity is said to be -dependent if it can exist in the database only when it is associated with another
related entity occurrence.
a. existence b. relationship
c. business d. data
38. If an entity can exist apart from all of its related entities, then it is existence-independent, and it is referred to as
a(n) entity.
a. weak b. alone
c. unary d. strong
39. A entity has a primary key that is partially or totally derived from the parent entity in the relationship.
a. strong b. weak
c. business d. child
Chapter 4: Entity Relationship (ER) Modeling
40. The existence of a(n) entity indicates that its minimum cardinality is zero.
a. ternary b. optional
c. strong d. weak
41. The Crow’s foot symbol with two vertical parallel lines indicates cardinality.
a. (0,N) b. (1,N)
c. (1,1) d. (0,1)
42. A relationship exists when an association is maintained within a single entity.
a. unary b. ternary
c. strong d. weak
43. A relationship exists when three entities are associated.
a. unary b. strong
c. ternary d. weak
44. If an employee within an EMPLOYEE entity has a relationship with itself, that relationship is known as a
relationship.
a. self b. self-referring
c. looping d. recursive
45. To simplify the conceptual design, most higher-order relationships are decomposed into appropriate equivalent
relationships whenever possible.
a. unary b. binary
c. strong d. weak
46. The entity relationship model uses the associative entity to represent a(n) relationship between two or
more entities.
a. M:N b. 1:M
c. N:1 d. M:1
47. When using the Crow’s Foot notation, the associative entity is indicated by relationship lines between the
parents and the associative entity.
a. dotted b. double
c. triple d. solid
Chapter 4: Entity Relationship (ER) Modeling
48. The first step in building an entity-relationship diagram (ERD) is .
a. developing the initial ERD
b. creating a detailed narrative of the organization’s description of operations
c. identifying the attributes and primary keys that adequately describe the entities
d. identifying the business rules based on the description of operations
49. If Tiny College has some departments that are classified as “research only” and do not offer courses, the
COURSE entity of the college database would be the DEPARTMENT entity.
a. existence-dependent on b. independent of
c. mandatory for d. optional to
50. In organizations that generate large number of transactions, are often a top priority in database design.
a. relationships among entities b. logical design standards
c. naming conventions d. high processing speeds
51. Complex requirements may dictate data transformations, and they may expand the number of entities
and attributes within the design.
a. information b. entity
c. design d. processing
52. are characteristics of entities.
53. A(n) attribute is an attribute that must have a value.
54. are underlined in an ER diagram.
55. A person’s Social Security number would be an example of a(n) attribute.
56. A(n) attribute need not be physically stored within the database.
57. A relationship is difficult to establish if only one side of the relationship is known.
Chapter 4: Entity Relationship (ER) Modeling
58. When indicating cardinality, the first value represents the number of associated entities.
59. The concept of relationship strength is based on how the of a related entity is defined.
60. A(n) relationship is also known as an identifying relationship.
61. The Crow’s Foot notation depicts the strong relationship with a(n) line between the entities.
62. A weak entity must be -dependent.
63. The Chen notation identifies a weak entity by using a double-walled entity .
64. Participation is if one entity occurrence does not require a corresponding entity occurrence in a
particular relationship.
65. In Crow’s Foot notation, an optional relationship between entities is shown by drawing a(n) on the side
of the optional entity.
66. Failure to understand the distinction between mandatory and optional in relationships might yield designs
in which awkward (and unnecessary) temporary rows (entity instances) must be created just to accommodate
the creation of required entities.
67. A relationship indicates the number of entities or participants associated with a relationship.
68. A(n) process is based on repetition of processes and procedures.
69. Identifying the attributes of entities helps in the better understanding of among entities.
70. not only helps database designers to stay on track during the design process, it also enables them to pick
up the design thread when the time comes to modify the design.
Chapter 4: Entity Relationship (ER) Modeling
71. Explain multivalued attributes with the help of examples. How are multivalued attributes indicated in the Chen
Entity Relationship model?
72. What is a weak relationship? Provide an example.
73. Explain mandatory participation in an entity relationship.
74. What is a ternary relationship? Provide some business rules examples that specify the need for a ternary or
higher- order relationship.
Chapter 4: Entity Relationship (ER) Modeling
75. Explain recursive relationships with the help of an example.