Datasheet

Each table in your database represents an object about your business, and each column in a table

represents an attribute of the object that the table represents. A row in the table represents a unique entry

for the object that the table defines.

To design a relational database, you must first identify all of the objects that will make up your database.

The term object is used to represent a set of information. You can also use the term entity in place of

object. An entity is an object that refers to a person, place, or thing. If you know that you will be building

an application that manages employees in your organization, you first identify which objects represent

the information about an employee. For example, an employee is an object and the employee’s manager

is an object.

Next, you want to identify which attributes make up the employee and manager objects. Tables 1-3 and 1-4

illustrate the attributes that have been identified for these objects.

Table 1-3: Employee Attributes

Attribute Description

Employee Name The name of the employee

Phone Number The phone number for the employee

Location The location where the employee works (for example, city, building, or

branch office)

Job Title The job title of the employee

Table 1-4: Manager Attributes

Attribute Description

Manager Name The name of the manager

Phone Number The phone number for the manager

Location The location where the manager works (for example, city, building, or

branch office)

Now that you have identified all the attributes for these objects, you must identify the tables to which

these attributes should be assigned. You can begin by defining the tables that will go into your database,

as shown in the Figure 1-2. Notice that the Employee Name and Manager Name have been separated

into two fields. This enables you to select and order employees and managers by first or last name.

Figure 1-2

Employee Table

FirstName

LastName

PhoneNumber

Location

JobTitle

Manager Table

FirstName

LastName

PhoneNumber

Location

Databases

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