Deck 6: Relational Databases and SQL

Question 1

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

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

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

Answer 3

False

Question 4

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

Question 5

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

Question 6

Attributes are often called fields.

Question 7

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

Question 8

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

Question 9

The first step in identifying all the relationships that should be included in a model is to identify users' existing and desired information.

Question 10

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

Question 11

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

Question 12

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

Question 13

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

Question 14

REA stands for resources,entities and agents.

Question 15

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

Question 16

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

Question 17

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

Question 18

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

Question 19

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

Question 20

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

Question 21

Knowledge management uses state-of-the art information technologies for storing and analyzing data to help managers make the best possible decisions for their companies.

Question 22

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

Question 23

Spreadsheets that are kept offline to an organization's enterprise systems can improve internal control.

Question 24

A missing value is called a non-null.

Question 25

Queries of a database are driven by SELECT commands.

Question 26

Which of the following is the entity or agent?

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

Question 27

The DELETE command is the method used to delete a tuple from a relation.

Question 28

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

Question 29

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

Question 30

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

Question 31

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 32

Business intelligence (BI)has been ranked as one of the top nine "key areas" of current developments in business information technology.

Question 33

Which of the following is the key attribute?

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

Question 34

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

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

Question 35

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

Question 36

An entity can be classified as all of the following except:

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

Question 37

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

Question 38

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

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

Question 39

Composite attributes consist of multiple subattributes.

Question 40

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

Question 41

Which of the following is a composite attribute?

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

Question 42

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 43

A key attribute is the attribute whose value is:

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

Question 44

Customers of Hanson Company,a home furnishings wholesaler,place orders by contacting a sales representative via a toll-free number.Which is the appropriate relationship type for this relationship?

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

Question 45

Common aspects of business intelligence include:

A) access to massive amounts of data
B) use spreadsheets
C) does not require an extensive overhaul of the information system
D) all of the above

Question 46

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 47

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's 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 48

____ 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 49

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 50

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

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

Question 51

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 52

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 53

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 54

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 55

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 56

Students at Macom University use a 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 57

Which relationship type does (1:N)mean?

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

Question 58

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 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 relationship type?

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

Question 61

Refer to Exhibit 6-1.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 62

Refer to Exhibit 6-1.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 63

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 64

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

Question 65

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

Question 66

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

Question 67

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

A) Table
B) Network
C) Field
D) Attribute

Question 68

Refer to Exhibit 6-1.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

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 70

Which of the following is a valid SQL command?

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

Question 71

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

Question 72

Refer to Exhibit 6-1.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 73

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 74

Which of the following commands allow us to join data across multiple tables to link specific pieces of information that are of interest?

A) Select
B) Project
C) Join
D) Display

Question 75

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

Question 76

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

Question 77

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 78

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 79

A simplified representation of a complex entity is a(n):

A) instance
B) attribute
C) model
D) relationship

Question 80

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

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