Question 1

Which of the following characterizes a relational database?

Accepted Answer

A relational database uses a series of logically related two-dimensional tables or files to store information in the form of a database.

Question 2

There are _____ primary steps in designing and building a database.

Accepted Answer

Using a database amounts to more than just using various DBMS tools.The four primary steps in designing and building a database include:1.Define entity classes and primary keys.2.Define relationships among entity classes.3.Define information (fields)for each relation (the term relation is often used to refer to a file while designing a database).4.Use a data definition language to create your database.

Question 3

Which of the following would be a good primary key for the entity class of students?

Accepted Answer

The primary key for each entity class uniquely defines each record or instance within the entity class.

Question 4

Why would you define business rules for a database?

Accepted Answer

Business rules are statements concerning the information you need to work with and the relationships within the information.These business rules will help you define the correct structure of your database.

Question 5

Which symbol would you use in an E-R diagram to show that a course is taught by only one teacher?

Accepted Answer

A | to denote a single relationship in an E-R diagram.

Question 6

Which symbol should you use in an E-R diagram to show the relationship between a student and the courses they are currently enrolled in?

Accepted Answer

A dotted line connecting entity classes denotes a relationship in an E-R diagram.

Question 7

Which of the following denotes a relationship between entity classes in an E-R diagram?

Accepted Answer

A dotted line connecting entity classes denotes a relationship in an E-R diagram.

Question 8

What is an instance?

Accepted Answer

An instance is an occurrence of an entity class that can be uniquely described with a primary key.

Question 9

Relational databases are similar to spreadsheets in that:

Accepted Answer

Relational databases are similar to spreadsheets in that you maintain information in two-dimensional files.In a spreadsheet,you place information in a cell (the intersection of a row and column).

Question 10

What is a primary key?

Accepted Answer

A primary key is a field (or group of fields in some cases)that uniquely describes each record.

Question 11

Which of the following is a graphic method of representing entity classes and their relationships?

Accepted Answer

An entity-relationship (E-R)diagram is a graphic method of representing entity classes and their relationships.

Question 12

Which of the following defines a database?

Accepted Answer

A database is a collection of information that you organize and access according to the logical structure of that information.

Question 13

Which of the following is true about an entity class?

Accepted Answer

An entity class is a concept-typically people,places,or things-about which you wish to store information and that you can identify with a unique key (called a primary key).

Question 14

What is the first step in designing and building a database?

Accepted Answer

The first step in designing and building a database involves defining entity classes and primary keys.

Question 15

_____ are statements concerning the information you need to work with and the relationships within the information.

Accepted Answer

Business rules are statements concerning the information you need to work with and the relationships within the information.

Question 16

An E-R diagram includes five basic symbols.Which one denotes an entity class?

Accepted Answer

An E-R diagram includes five basic symbols: a rectangle denotes an entity class.

Question 17

An E-R diagram includes five basic symbols.Which of the following denotes a single relationship between entity classes?

Accepted Answer

The symbol "|" denotes a single relationship in an E-R diagram.

Question 18

A supplier is an example of a(n)____.

Accepted Answer

An entity class is something like a student,a supplier,a book,and so on.

Question 19

An organization wishes to store information about its employees in a database.The employees,in this case,constitute a(n)____.

Accepted Answer