Deck 2: The Relational Model: Introduction, Qbe, and Relational Algebra

Question 1

The Access query design grid contains the ProductID, ProductName, and Rating fields. How can you omit the Rating field from the query results but use it to set a criterion for the query?

A) Delete the Rating field from the query design grid.
B) Add a second copy of the Rating field to the query design grid.
C) Clear the checkmark from the Rating field's Show check box.
D) Change the query to an update query.

Answer 1

C

Question 2

Which of the following is NOT true about a relation, otherwise known as a two-dimensional table?

A) The entries in the table should be single-valued.
B) All values in a column should be values of the same attribute.
C) Two or more columns can share the same name.
D) The order of rows is not important.

Answer 2

C

Question 3

In relational algebra, which command retrieves rows from a table based on specified criteria?

A) SELECT
B) JOIN
C) CREATE
D) UNION

Answer 3

A

Question 4

In Access, if you want a query to list the ProductID, Category, and Description field values and sort the records by description within each category, how should you arrange the fields from left to right in the query design grid?

A) ProductID, Description, Category
B) Description, Category, ProductID
C) Description, ProductID, Category
D) ProductID, Category, Description

Question 5

Which aggregate function do you use to total the values in a numeric field in a group of records?

A) Sum
B) Total
C) Count
D) Max

Question 6

A relational database handles entities, attributes, and relationships by storing each entity in its own row.

Question 7

In Access a(n) _____ query permanently removes all the records from the selected table(s) that satisfy the criteria entered in the query.

A) update
B) delete
C) make-table
D) parameter

Question 8

In Access, what uniquely identifies a row in a table?

A) attribute
B) column
C) primary key
D) field

Question 9

The attributes of an entity become the fields or columns in a table.

Question 10

To select data from more than one table at the same time, you need to perform a make-table query.

Question 11

If you are creating a computed field that adds 10 percent to the UnitPrice field, how do you enter the UnitPrice field name in the expression?

A) "UnitPrice"
B) Unit Price
C) [UnitPrice]
D) (UnitPrice)

Question 12

If you want to select records containing the text Consulting in the ProjectType field, how does Access save the criterion in the query grid of Query Design View?

A) "Consulting"
B) #Consulting#
C) [Consulting]
D) (Consulting)

Question 13

In Access, you can display the results of a select query using the Run button or the View button.

Question 14

Which database term refers to a row in a table?

A) tuple
B) field
C) group
D) relation

Question 15

Microsoft Access uses Query Design View as a QBE.

Question 16

A _____ is a question about the data structured in a way that the DBMS can recognize and process.

A) query
B) product
C) relationship
D) tuple

Question 17

What happens when you run a select query in Access?

A) Access creates a unique copy of the data.
B) Access selects current data from underlying tables.
C) Access creates a table with the specified fields and records.
D) Access locks the underlying tables so they cannot be changed.

Question 18

When you can determine the value of a field using information from existing fields in a record in a query, you should create a(n) _____.

A) argument
B) compound condition
C) grouping field
D) computed field

Question 19

The field you use to sort records is called the _____.

A) sort key
B) sort argument
C) parent key
D) foreign key

Question 20

In Access, if you want to be able to enter different criteria each time you run a query, create a(n) _____ query.

A) update
B) parameter
C) run-time
D) aggregate

Question 21

For a one-to-many relationship in the Access Relationships window, how can you tell which table is the "many" table?

A) The one symbol identifies the "many" table.
B) The "many" table always appears to the left of the "one" table.
C) The "many" table always appears below the "one" table.
D) An infinity symbol identifies the "many" table.

Question 22

In general, what should be in place before you select fields from more than one table in Access Query Design View?

A) The tables should not contain fields with the same field name.
B) The tables should be merged into one table.
C) The join line between the tables should be deleted.
D) The tables should be related in a proper one-to-many relationships.

Question 23

You can create compound criteria (conditions) in a query by using which of the following two keywords?

A) AND, OR
B) AND, NOR
C) OR, NOT
D) NOT, ONLY

Question 24

What type of functions are Count, Sum, Avg, Max, and Min?

A) accumulation
B) allowed
C) primary
D) aggregate

Question 25

In an Access query, how can you list records in A-Z order by last name?

A) Set an ascending sort order on the LastName field.
B) Group the LastName field.
C) Set a descending sort order in the LastName field.
D) Remove the checkmark from the Show box in the LastName field.

Question 26

Which of the following expressions in Access Query Design View creates a computed field named MonthlySalary using a value from the Salary field?

A) MonthlySalary = [Salary / 12]
B) MonthlySalary: [Salary] / 12
C) Salary / 12 = [MonthlySalary]
D) MonthlySalary: "Salary" / 12

Question 27

Based on the following table, which relational algebra command creates a new table named CustState containing the fields CustomerNum and State? Customer (CustomerNum, CustomerName, Street, City, State, PostalCode)

A) JOIN Customer WITH (CustomerNum, State) GIVING CustState
B) PROJECT Customer OVER (CustomerNum, State) GIVING CustState
C) SELECT Customer OVER (CustomerNum, State) GIVING CustState
D) MAKE-TABLE CustState FROM Customer WITH (CustomerNum, State)

Question 28

What do you call the field used to join two tables on the "many" side of a one-to-many relationship?

A) foreign key field
B) primary key field
C) secondary sort field
D) calculated field

Question 29

A ____________________ in a record is the result of a calculation using data from the rest of the record.

A) foreign key field
B) composite field
C) grouping field
D) computed field

Question 30

If you use ____________________ criteria, each criterion must be true for a record to be selected.

A) OR
B) aggregate
C) AND
D) BOTH

Question 31

Which of the following fields would be the best candidate for a primary key field in a table of employee data?

A) LastName
B) EmployeeID
C) Email
D) BirthDate

Question 32

In relational algebra, what command is used to identify certain columns?

A) SELECT
B) DELETE
C) PROGRAM
D) PROJECT

Question 33

Which of the following criteria selects all records containing a value greater than 250?

A) ="250"
B) 250
C) <>250
D) >250

Question 34

Which of the following is a technique for increasing the speed of Access queries?

A) Use Query Design View to join tables.
B) Type field names directly into the query design grid.
C) Include fields considered optional for the query.
D) Delete field lists that are not needed for the query.

Question 35

What type of query could you run to remove records with a product ID of 702 from the Products table?

A) update query
B) difference query
C) delete query
D) parameter query

Question 36

What type of Access query creates a new table using the query results?

A) new-table
B) make-table
C) create-table
D) merge-table

Question 37

Based on the following notation, which relational algebra command would list all information from the table concerning the customer with numeric CustomerNum 260? Customer (CustomerNum, CustomerName, Street, City, State, PostalCode)

A) SELECT Customer 260 RESULTS Answer
B) SELECT Customer WHERE CustomerNum=260 GIVING Answer
C) SELECT Customer GIVING Answer WHERE CustomerNum='260'
D) SELECT Customer WHERE CustomerNum='260' RESULTS Answer

Question 38

What type of Access query changes data?

A) addition
B) projection
C) update
D) select

Question 39

If you are sorting records by more than one field, which field is the first field that is evaluated for sorting purposes?

A) primary sort key
B) secondary sort key
C) maximum sort key
D) minor sort key

Question 40

In the Access QBE, where do you specify criteria for a query?

A) in the upper pane of Query Design View
B) in the Criteria row of the query design grid
C) in Datasheet view of the query
D) in the Navigation Pane

Question 41

Discuss the difference between the major sort key and the minor sort key using an example.

Question 42

List five aggregate functions available in Access.

Question 43

What is the difference between the records that are selected when AND criteria versus OR criteria in a query?

Question 44

In Access Query Design View, which of the following expressions calculates the number of days between today's date and a field named DueDate?

A) Date - DueDate
B) Today - [DueDate]
C) Day() - [DueDate]
D) Date() - [DueDate]

Question 45

Explain what relational algebra is and provide an example showing how it is used.

Question 46

How are aggregate functions different from other types of functions?

A) Aggregate functions make calculations on groups of records.
B) Aggregate functions return yes/no or true/false values.
C) Aggregate functions work only with numeric data.
D) Aggregate functions do not work with date values.

Question 47

List six properties that define a relation, a two-dimensional table.

Question 48

Which of the following Access functions can you use to return the number of records in a group of records?

A) Group
B) Count
C) Total
D) Number

Question 49

If you use an aggregate function in a query to determine the average values in a Bonus field, what default field name does Access use for the column with the calculations?

A) Bonus
B) Average Bonus
C) BonusAvg
D) AvgOfBonus

Question 50

In Access Query Design View, how do you add the Total row to the query design grid?

A) Click the Totals button on the Query Tools Design tab.
B) Click the Group by arrow in the Criteria row, and then click Total.
C) Click the Grouping button on the Query Tools Design tab.
D) Drag the Total field to the query design grid.