Exploring MicrosoftAccess 2003

Chapter 5

One-to-Many Relationships: Subforms

and Multiple Table Queries

Objectives (1 of 2)

• One-to-many relationship essential in database design

• Use the Relationship window

• Define referential integrity

• Distinguish between a main form and a subform

Objectives (2 of 2)

• Create a query based on multiple tables

• Create a main form with two subforms

Overview

• One-to-many relationships between tables is the real power of Access

• Primary key of one table is foreign key of the related table

• Referential integrity ensures consistency between tables

• Main forms and subforms created from related tables.• Reports based on a multiple-table query

Case StudyConsumer Loans

• Understanding the need for a relational database• One-to-many relationship – use Relationships

window• Need a primary key, a unique identifier• Foreign key in the ‘many’ table is the primary key

in the ‘one’ table• Enforce referential integrity

Relationships Window

ConsultantID is primarykey in Consultant table

Relationship line

ConsultantID is foreignkey in Clients table

Referential Integrity

Delete Record button

Click + to displayrelated records

You cannot delete a Consultant without first deleting related Clients

One-to-Many Relationships

Hands-On Exercise 1

• Open the National Bank Database• Create and Delete Relationships• Add a Customer Record• Add a Loan Record• Referential Integrity• Close the Database

Subforms

• Subform is a form within a form• Main form would be based on primary table

while subform is based on related table• Use Subform Wizard• Can be created either on main form or dragged

from a separate form

Subform

Consultant C01

Client related toConsultant C01

Status bar forClients form

Status bar forConsultants form

Creating a Subform

Hands-On Exercise 2

• Create Customers Form using Form Wizard• Modify Customers Form• Create Loans Subform• View Customers Form• Add Payment Amount• Enter a New Loan• Print the Form

Multiple Table Queries

• Query information from two tables

• Create a select query using both tables

• Query window displays selected fieldsof each table

Multiple Table Queries

Run button

Column selector

Select table

Enter criteria

Queries and Reports

Hands-On Exercise 3

• Create a Select Query

• Move and Size the Field Lists

• Create and Run the Query

• Create and Print a Report

Expanding the Database

• Can expand a database without disturbing existing tables

• Use relationship window to establishhow fields from specific tables will be related

• Can use multiple subforms

Linked Subforms

Hands-On Exercise 4• Add a relationship• Create the Payments Subform• Change the Default View• The Loans Subform in Form View• The Customers Form• The Finishing Touches• Make Your Payments

Chapter 5 Summary (1 of 2)

• Access database may contain multiple tables• Each table has a primary key which is the

foreign key of a related table• Relationships window to create one-to-many

relationships• Referential integrity ensures consistency

between related tables

Chapter 5 Summary (2 of 2)

• Subform is a form within a form

• A main form can have multiple subforms

• Select query can include fields from several tables

• Tables can be added at any time withoutdisturbing existing data

Practice with Access (1 of 2)

1. Adding Clip Art

2. The Report Wizard

3. Employees by Location

4. Employees by Title

Practice with Access (2 of 2)

5. The Switchboard

6. The Table Analyzer Wizard

7. Synchronizing Reports

8. Data Access Pages

Case Studies

• Recreational Sports League

• The Personnel Director

• The Franchise

• Widgets of America