Question 1

Rows are also called ____.
A)fields
B)tuples
C)columns
D)attributes

Accepted Answer

Rows in a relational database are commonly referred to as tuples, which represent a single record within a table. Fields or attributes refer to individual pieces of data within a record, while columns refer to the vertical alignment of data in a table.

Question 2

The attributes of an entity become the rows or records in a table.

Accepted Answer

Attributes of an entity become the columns or fields in a table, while each row or record represents a single instance of that entity.

Question 3

When duplicate column names exist in a database and you need to indicate the column to which you are referring,____.
A)do not use these two tables together
B)do not use the column names in the same statement
C)write the table name only
D)write both the table name and the column name,separated by a period

Accepted Answer

When duplicate column names exist in a database, the best choice is to write both the table name and the column name, separated by a period. This clearly indicates which column is being referenced and avoids any ambiguity.

Question 4

A relation is essentially just a two-dimensional table.

Accepted Answer

A relation is a two-dimensional table consisting of rows and columns where each row represents a record and each column represents an attribute or field of that record. It is a fundamental concept in relational database management systems.

Question 5

A relational database is a collection of relations.

Accepted Answer

A relational database is made up of tables that contain relations between data points in the form of rows and columns. Each table represents a relation between entities, and the database as a whole is a collection of these relations.

Question 6

The comparison operators are also known as relational operators.

Accepted Answer

This statement is true. The comparison operators (such as <, >, <=, >=, ==, !=) are also referred to as relational operators.

Question 7

In a relation,the order of rows is important.

Accepted Answer

In a relation, the order of rows is not important. The rows can be arranged in any order and it does not affect the meaning of the relation. The important aspect is the relationship between the columns/attributes.

Question 8

Based on the statement below,which of the following is the primary key? Part (PartNum,Description,OnHand,Class,Warehouse,Price)
A)PartNum
B)Description
C)Class
D)Warehouse

Accepted Answer

The best choice for the primary key would be PartNum as it uniquely identifies each record and is essential for any operations performed on the table. The other attributes may have duplicate values, making them unsuitable for primary key designation on their own. However, a composite primary key may be possible using PartNum in combination with another attribute.

Question 9

A relation is a(n) ____.
A)attribute
B)column
C)field
D)table

Accepted Answer

A relation refers to a table in a database, which contains a set of related and structured data. Therefore, the correct choice is D, i.e., table.

Question 10

Access automatically adds double quotation marks around values in the design grid that are formatted as Text fields when you run the query or move the insertion point to another cell in the design grid.

Accepted Answer

This is true. Access automatically adds double quotation marks around values in Text fields in the design grid when you run the query or move the insertion point to another cell in the grid. This is because text values need to be enclosed in quotation marks to distinguish them from other types of values, such as dates or numbers.

Question 11

In a relation,the order of the columns is immaterial.

Accepted Answer

In a relation, the order of the columns is irrelevant because the data can still be accessed and manipulated using SQL queries regardless of the order in which the columns are displayed.

Question 12

When a field name contains spaces or SQL reserved words,you must enclose the field name in curly braces ({}).

Accepted Answer

In SQL, field names containing spaces or reserved words are typically enclosed in square brackets ([]) or double quotes (""). Curly braces are not used for this purpose.

Question 13

QBE is a visual approach to writing queries.

Accepted Answer

QBE stands for Query by Example, which is a visual approach to writing queries in a graphical user interface.

Question 14

In an OR criterion,the overall criterion is true if either of the individual criteria is true.

Accepted Answer

In an OR criterion, the overall criterion is true if either of the individual criteria is true.

Question 15

The ____ key of a table is the column or collection of columns that uniquely identifies a given row in that table.
A)primary
B)secondary
C)foreign
D)minor

Accepted Answer

The primary key of a table is the column or collection of columns that uniquely identifies a given row in that table. This key is used to enforce data integrity by ensuring that each row in the table is distinct and can be identified uniquely. Secondary keys are used for indexing and searching but do not enforce uniqueness. Foreign keys are used to establish relationships between tables. Minor keys are not a recognized concept in database design.

Question 16

The concept of grouping means that statistics will be calculated for individual records.

Accepted Answer

The concept of grouping involves combining records into categories or groups, and then calculating statistics for each group rather than for individual records.

Question 17

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

Accepted Answer

In a relational database, each entity is stored in its own table and attributes and relationships are represented through the use of columns and foreign keys.

Question 18

The secondary key provides an important way of distinguishing one row in a table from another.

Accepted Answer

A secondary key is used for indexing and improving search performance, not for uniquely identifying rows; that is the role of a primary key.

Question 19

The comparison operators are +,*,%,and /.

Accepted Answer

The comparison operators are actually ==, !=, <, >, <=, and >=. The operators mentioned (+, *, %, and /) are arithmetic operators.

Question 20

An unnormalized relation is a table that has more than one row.

Accepted Answer

An unnormalized relation is a table that has redundant data or repeating groups. It is not defined by the number of rows in a table. A table can have multiple rows and still be normalized if it does not have redundant data or repeating groups.

Quiz 2: The Relational Model 1: Introduction, QBE, and Relational Algebra

Rows are also called ____.