Deck 6: Relational Databases and Sql

Question 1

A model is a complex representation of a simple entity or phenomenon.

Answer 1

False

Question 2

A legacy system is one that has existed in an organization for less than one year.

Answer 2

False

Question 3

Relationships map and define the way in which data can be extracted from a database.

Answer 3

True

Question 4

A collection of data representing multiple occurrences of a resource, event, or agent is known as a relation.

Question 5

Attributes are often called fields.

Question 6

The customer street address is often used as the key attribute in an REA diagram.

Question 7

REA stands for resources, entities and agents

Question 8

A recursive relationship is created when there is an employee being supervised, and another employee is the supervisor.

Question 9

The fundamental requirement for moving toward an event driven model is the complete integration of data related to an organization's business events.

Question 10

Representing supervisors and their employees as separate entities in the model can lead to data redundancy.

Question 11

A recursive relationship occurs between two different instances of an entity.

Question 12

In an REA diagram, the rectangle is used to represent the composite attribute.

Question 13

A primary attribute is the attribute whose value is unique for every entity that will appear in the database.

Question 14

An entity in an accounting system can be classified as a resource, event or agent about which data are collected.

Question 15

The cardinality constraint is used to specify both the minimum and maximum participation of one entity in the relationship with the other entity.

Question 16

The first step in REA is evaluating the attributes.

Question 17

The notation of (1,1) is used to specify the relationship type of one to many.

Question 18

The cardinality constraint is used less frequently than the participation constraint.

Question 19

A set of data that describes an instance of the entity represented by a relation is known as a tuple.

Question 20

The notation 1,N is used to specify the relationship type of one to many.

Question 21

A data field in a traditional file is similar to a relational:

A)table
B)attribute
C)tuple
D)row

Question 22

An entity can be classified as all of the following except

A)resource
B)event
C)tuple
D)agent

Question 23

SQL is a powerful database language that can be used to define database systems, query the database for information, generate reports from the database, and access databases from within programs using embedded commands.

Question 24

Queries of a database are driven by SELECT commands.

Question 25

A relation in an ER model is the same as an entity in the REA model.

Question 26

A(n) ____ of an entity is on specific thing of the type defined by the entity.

A)agent
B)composite attribute
C)attribute
D)instance

Question 27

Which of the following is an attribute but least likely to be the key attribute?

A)client
B)client number
C)client name
D)client street address

Question 28

Which of the following is a composite attribute?

A)client
B)client number
C)client name
D)client street address

Question 29

The INSERT command is used to add a single tuple to an existing relation.

Question 30

Which of the following is the entity or agent?

A)client
B)client number
C)client name
D)client street address

Question 31

Relational integrity specifies that for every attribute in one relation that has been specified to allow reference to another relation, the tuple being referenced must remain intact.

Question 32

A key attribute is the attribute whose value is:

A)undeterminable
B)unique
C)large
D)the same for all attributes

Question 33

A(n) ____ is an item of data that characterizes an entity or relationship

A)agent
B)composite attribute
C)attribute
D)instance

Question 34

The DELETE command is used when we want to change one or more attribute values.

Question 35

Most DBMS available today that include SQL also include mechanisms within the DBMS itself for establishing and enforcing referential integrity.

Question 36

A missing value is called a non-null.

Question 37

Which of the following is the key attribute?

A)client
B)client number
C)client name
D)client street address

Question 38

The secondary key is specified to uniquely identity each tuple in the relation.

Question 39

For the following entity and attribute model, what would be the key attribute of the Students entity?

A)social security number
B)name
C)address
D)street

Question 40

The UPDATE command demonstrates one of the weaknesses in most forms of SQL.

Question 41

Students at Macom University use an web-based course registration system.Identify the participation constraint of the following data model relationship.The university maintains student records until they graduate or do not enroll in a course for a 3-year period.

A)N:M
B)1:N
C)(1,1):(0,N)
D)(1,1):(1,N)

Question 42

____ specifies that for every attribute value in one relation that has been specified in order to allow reference to another relation,the tuple being referenced must remain intact.

A)Cardinality constraint
B)Participation constraint
C)Referential integrity
D)Economic constraint

Question 43

The constraint that is specifies the degree of minimum participation of one entity in the relationship with the other entity is called:

A)cardinality constraint
B)participation constraint
C)economic constraint
D)logical constraint

Question 44

A situation in which a particular supplier provides more than one type of inventory item to a firm and a particular type of inventory item is acquired from more than a single supplier is called a(n):

A)one-to-one relationship
B)one-to-many relationship
C)many-to-many relationship
D)entity relationship

Question 45

A set of data that describes an instance of the entity represented by a relation is known as a(n) ____.

A)tuple
B)resource
C)agent
D)event

Question 46

The cardinality constraint:

A)specifies the degree of minimum participation of one entity in the relationship with the other entity.
B)provides more information than the participation constraint.
C)is the most common constraint specified in E-R diagrams.
D)all of the above.

Question 47

Which of following is not a step in the process for specifying relations based on REA diagrams?

A)Determine the attributes for each of the entities.
B)Determine the number of tables.
C)Create a separate relational table for each entity.
D)Implement the relationships among the entities.

Question 48

Legacy systems do not usually have which of the following characteristics?

A)developed on previous hardware (and/or software) platforms
B)are easily adaptable to enterprise systems
C)have been used by an organization for a long period of time
D)all of the above are typical characteristics of legacy systems

Question 49

Which relationship type does (1, N) mean?

A)one-to-many
B)one-to-one
C)one-to-few
D)many-to-many

Question 50

The mapping of the relationships between entities would be used in the development of a(n):

A)context diagram
B)logical DFD
C)physical DFD
D)REA Model

Question 51

Customers of Hanson Company, a home furnishings wholesaler, place orders by contacting a sales representative via a toll-free number.Identify the constraints of the following data model relationship.

A)1:1
B)1:N
C)N:M
D)N:1

Question 52

The sequence of steps in identifying relationships in a model is:

A)evaluate entities as pairs, identify user existing and desired information, evaluate each entity to determine if there is any need for two occurrences of the same entity type to be linked
B)identify user existing and desired information, evaluate entities as pairs, evaluate each entity to determine if there is any need for two occurrences of the same entity type to be linked
C)evaluate entities as pairs, evaluate each entity to determine if there is any need for two occurrences of the same entity type to be linked, identify user existing and desired information
D)evaluate each entity to determine if there is any need for two occurrences of the same entity type to be linked, evaluate entities as pairs, identify user existing and desired information

Question 53

The following E-R diagram shows a M:N relationship between two relations.To map this E-R diagram into a logical database model:

A)divide the content of the Course relation to establish two relations having 1:N relationships
B)add the primary key of the Student relation as an attribute in the Course relation
C)create a new relation whose primary key is a composite of the primary keys of two relations
D)add the primary key of the Course relation as an attribute in the Student relation

Question 54

Which of the following statements about the participation constraint is false?

A)It specifies the degree of minimum participation of one entity in the relationship with the other entity.
B)The constraint is either 1 or 0.
C)It is the most common constraint in E-R diagrams.
D)It provides more information than the cardinality constraint.

Question 55

To generate a standard report of a relational database, which of the following SQL commands would be used?

A)Select report
B)Select view
C)Create report
D)Create view

Question 56

Enterprise systems are integrated software packages designed to provide complete integration of:

A)an organization's accounting information system
B)an organization's business data
C)an organization's business information processing systems and all related data
D)an organization's management

Question 57

Which of the following is not a relationship type?

A)one-to-many
B)one-to-one
C)one-to-few
D)many-to-many

Question 58

In a relational database, a relation is defined as a collection of data representing multiple occurrences of the following except:

A)a resource
B)an event
C)an activity
D)an agent

Question 59

____ are defined as a set of data that describes an instance of the entity represented by a relation.

A)Attributes
B)Tuples
C)Primary keys
D)Candidate keys

Question 60

Which of the following is not a proper SQL command for creating database relations?

A)Create table employee
B)Create table training_completed
C)Create client
D)Alter table release_time

Question 61

In a relational database, the entity is represented as a(n):

A)table
B)network
C)field
D)attribute

Question 62

The SELECT statement has all but one of the following parts
a.a list of attributes that we wish to SELECT from the database
b.a WHEN clause
c.a list of tables where these attributes can be found
d.a WHERE clause

Question 63

Which is not an SQL command in which data can be changed in the database?

A)INSERT
B)DELETE
C)UPDATE
D)CREATE

Question 64

The relationship that relates to the specification of how many occurrences of an entity can participate in the given relationship with any one occurrence of the other entity in the relationship is referred to as ______________________________.

Question 65

REA stands for ____________________, ____________________, and ____________________.

Question 66

Which is not a step in creating a relation using SQL?

A)assign the relation a name
B)assign each attribute a name
C)specify the constraints on the attributes
D)specify the attributes of the constraints

Question 67

Which of the following SQL statements would extract the client number and date for every instance that an employee worked less than 8 hours any particular day?

A)QUERY BILLING_HOURS SELECT Client_No, Date
WHERE Hours<8
B)QUERY client_No, Date FROM BILLING_HOURS
WHERE Hours>8
C)SELECT Client_No, Date WHERE Hours<8
D)SELECT Client_No, Date FROM BILLING_HOURS
WHERE Hours<8

Question 68

Which of the following SQL statements would extract the employee number and date for every instance that had a billing rate of $150?

A)SELECT Employee_No, Date FROM BILLING_HOURS
WHERE Rate=150
B)QUERY Employee_No, Date FROM BILLING_HOURS
WHERE Rate=150
C)SELECT Employee_No, Date WHERE Rate=150
D)QUERY BILLING_HOURS SELECT Employee_No, Date
WHERE Hours>8

Question 69

Which of the following SQL statements would extract the client number and date for every instance that had a billing rate of $150?

A)QUERY BILLING_HOURS SELECT Client_No, Date
WHERE Rate=150
B)QUERY client_No, Date FROM BILLING_HOURS
WHERE Rate=150
C)SELECT Client_No, Date WHERE Rate=150
D)SELECT Client_No, Date FROM BILLING_HOURS
WHERE Rate=150

Question 70

Attributes that consist of multiple subattributes are referred to as _________________________.

Question 71

A(n) ______________________________ relationship occurs between two different instances of an entity.

Question 72

A(n) _________________________ is the attribute whose value is unique for every entity that will ever appear in the database.

Question 73

Which of the following relational commands would a manager use to combine the data from two related relations into a third relation?

A)select
B)project
C)join
D)display

Question 74

Which of the following is a valid SQL command?

A)MODIFY
B)INSERT
C)ADD
D)APPEND

Question 75

The notation 1,N is used to specify the relationship type of _________________________.

Question 76

A(n) ____________________ is an item of data that characterizes an entity or relationship.

Question 77

Which of the following SQL statements would extract the employee number and date for every instance that an employee worked more than 8 hours any particular day?

A)SELECT Employee_No, Date FROM BILLING_HOURS
WHERE Hours>8
B)QUERY Employee_No, Date FROM BILLING_HOURS
WHERE Hours>8
C)SELECT Employee_No, Date WHERE Hours>8
D)QUERY BILLING_HOURS SELECT Employee_No, Date
WHERE Hours>8

Question 78

A(n) ____________________ in an accounting system can be classified as a resource, event, or agent about which data is collected.

Question 79

The ______________________________ specifies the degree of minimum participation of one entity in the relationship with the other entity.

Question 80

____________________ map and define the way in which data can be extracted from a database.