1. Exploring Microsoft Access 2003
Chapter 5
One-to-Many Relationships: Forms - Subforms
and Multiple Table Queries

2. 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

3. Objectives (2 of 2) Create a query based on multiple tables
Create a main form with two subforms

4. 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

5. Case Study Consumer 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

6. Relationships Window ConsultantID is primary key in Consultant table
Relationship line
ConsultantID is foreign
key in Clients table

7. Referential Integrity
Delete Record button
Click + to display
related records
You cannot delete a Consultant without first deleting related Clients

8. 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

9. Forms
Used as interfaces over tables or queries
different components:
- bound controls
- unbound controls
- calculated controls
- drop-down list box (combo box)
- check box
- option group
- command buttons
- list box

12. Controls can be bound, unbound, or calculated:
Bound control  A control whose source of data is a field in a table or query is called a bound control. You use bound controls to display values that come from fields in your database. The values can be text, dates, numbers, Yes/No values, pictures, or graphs. For example, a text box that displays an employee's last name might get this information from the Last Name field in the Employees table.
Unbound control  A control that doesn't have a source of data (such as a field or expression) is called an unbound control. You use unbound controls to display information, pictures, lines or rectangles. For example, a label that displays the title of a form is an unbound control.

13. Calculated control  A control whose source of data is an expression, rather than a field, is called a calculated control. You specify the value that you want to use as the source of data in the control by defining an expression. An expression can be a combination of operators (such as = and + ), control names, field names, functions that return a single value, and constant values. For example, the following expression calculates the price of an item with a 25 percent discount by multiplying the value in the Unit Price field by a constant value (0.75).
=[Unit Price] * 0.75

14. Subforms

15. Subforms are generated using Wizard

16. 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

17. Subform Consultant C01 Client related to Consultant C01 Status bar for
Clients form
Status bar for
Consultants form

18. 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

19. Multiple Table Queries
Query information from two tables
Create a select query using both tables
Query window displays selected fields of each table

20. Multiple Table Queries
Run button
Column selector
Select table
Enter criteria

21. 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

22. Expanding the Database
Can expand a database without disturbing existing tables
Use relationship window to establish how fields from specific tables will be related
Can use multiple subforms

23. 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

25. 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

26. 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 without disturbing existing data

27. Practice with Access (1 of 2)
1. Adding Clip Art
2. The Report Wizard
3. Employees by Location
4. Employees by Title

28. Practice with Access (2 of 2)
5. The Switchboard
6. The Table Analyzer Wizard
7. Synchronizing Reports
8. Data Access Pages

29. Case Studies Recreational Sports League The Personnel Director
The Franchise
Widgets of America