Create and Edit Databases

Module 7 Lesson 2

Steps to Design a Database

1. Plan and design the database according to needs and requirements

2. Determine the fields or categories that will be used in the database

3. Determine field properties to include size and type

Last Name First Name Employee Number

Hours of Work

Rate of Pay

Gross Pay

Step 1: Plan and Design

Last Name First Name Employee Number

Hurs Worked

Rate of Pay

Gross Pay

Step 2: Determine the Fields

Step 3: Determine Field Properties

• Currency ($)• Date (03/03/03)• Numeric (450)

– These numbers can be used in calculations• I.E. Gross pay, basketball statistics, etc.

• Text/General (Smith)– Numbers may used, but would not be

computed• I.E. Social security numbers, telephone numbers,

etc.

Last Name First Name Employee Number

Hours Worked

Rate of Pay Gross Pay

Smith Stacy 001 40 $5.00 $200.00

Carter Sherrell 002 30 $7.00 $210.00

Allen Donald 003 25 $10.00 $250.00

Example of a Database File

Database File: This is your main file that encompasses the entire database and that is saved to your hard-drive or floppy disk. (Example--StudentDatabase.mdb)

Table:A table is a collection of data about a specific topic. There can be multiple tables in a database. (Example #1—Students) (Example #2—Teachers)

Field:Fields are the different categories within a Table. Tables usually contain multiple fields. (Example #1--Student LastName)(Example #2--Student FirstName)

Datatypes:Datatypes are the properties of each field. A field only has 1 datatype. (Example: LastName; Datatype=Text)

First of all you need to understand how Microsoft Access breaks down a database. Some keywords involved in this process are: Database File, Table, Record, Field, Data-type. Here is the Hierarchy that Microsoft Access uses in breaking down a database.

Tables A table is a collection of data about a specific topic, such as students or contacts. Using a separate table for each topic means that you store that data only once, which makes your database more efficient, and reduces data-entry errors. Therefore, you may have multiple tables in a database.Tables organize data into columns (called fields) and rows (called records).

Tables

Primary Key •One field (column) whose value or values uniquely identify each record in a table. A primary key does not allow Null values and must always have a unique value. A primary key is used to relate a table to foreign keys in other tables. •NOTE: You do not have to define a primary key, but it's usually a good idea. If you don't define a primary key, Microsoft Access asks you if you would like to create one when you save the table.

Primary Key

Datasheet View Design View

Displays the view, which allows you to enter raw data into your database table.

Displays the view, which allows you to enter fields, data-types, and descriptions into your database table.

Switching Views •To switch views between the datasheet (spreadsheet view) and the design view, simply click the button in the top-left hand corner of the Access program.

Views in a Database

Video Demonstration: Editing and More Editing

Click the button for a brief video. A new

website will open, be sure to return to this

presentation.