Access07 l1 ch2

Copyright 2007, Paradigm Publishing Inc.

ACCESS 2007Chapter 2

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OBJECTIVES

• Creating Related Tables

• Determining Relationships

• Primary Keys• Foreign Keys• Relationships• Referential

Integrity• Printing

Relationships• Subdatasheets• Features

Summary

CREATING RELATIONSHIPS BETWEEN DATABASE TABLES

Chapter 2Chapter 2

Microsoft Access 2007 – Level 1Microsoft Access 2007 – Level 1



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OBJECTIVES






Summary

Performance ObjectivesPerformance Objectives

• Create a database table with a primary key

• Create a database table with a foreign key

• Create a relationship between database tables

• Print table relationships• Display Subdatasheets



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OBJECTIVES






Summary

Creating Related TablesCreating Related Tables

• Access is a relational database management system

• Relationships are defined between sets of data (tables)– allows greater flexibility in manipulating

data– eliminates redundancy



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Summary

Determining RelationshipsDetermining Relationships

Planning is most important Break down fields into tables to avoid redundancies

Clients tableClient #ClientStreet AddressCityStateZip Code

Insurance tableLicense #Client #Insurance CodeUninsured Motorist

Coverage tableInsurance CodeType of Insurance

Claims tableClaim #Client #License #Date of ClaimAmount of Claim

Notice that eachtable is about

only one subject

Some fields appearin more than one

table – they are used to create

a relationship



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Summary

Creating a Primary FieldCreating a Primary Field

• Need to designate a primary (key) field in a table before creating a relationship between tables

• Must contain unique data

• Access enforces Entity Integrity– expects a value in the primary field in

each record– cannot close a table containing a null

value in a primary (key) field



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Summary

Creating a Primary Field…/2Creating a Primary Field…/2

Open table in Design view

Position insertio

npoint in

field

Click Primary Key button

Notice image of key

To define more than one field as the primary key, select the rows and click the Primary

Key button



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Summary

Creating a Foreign KeyCreating a Foreign Key

A primary key field in one tablemay be a foreign key in another

Primary key and foreign key form

a relationshipbetween the tables

Clients tableClient #ClientStreet AddressCityStateZip Code

Insurance tableLicense #Client #Insurance CodeUninsured Motorist

Coverage tableInsurance CodeType of Insurance

Claims tableClaim #Client #License #Date of ClaimAmount of Claim



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Summary

Establishing a RelationshipEstablishing a Relationship

• Relate one table to another by joining the tables– data can be extracted from both tables

• Define the type of relationship to be created– one record in the primary table will match

zero, one, or many records in the related table (one-to-one, or one-to-many)

• Set Referential Integrity– a record must be added to the “one” table

before it can be added to the “many” table



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Summary

Creating a One-to-Many RelationshipCreating a One-to-Many Relationship

Open database file

Click Database Tools tab,

Relationships

Show Table dialog box appears when no

relationships have been defined yet



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Summary

Creating a One-to-Many Relationship…/2Creating a One-to-Many Relationship…/2

Double-click each table to add it to the Relationships

window

After adding all the tables

Repeat until all required tables are

added

Click Closewhen done adding

Notice that the Primary keys are indicated



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Summary


Drag the common field from the primary table(the “one”) to the related table (the “many”)

Edit Relationshipsdialog box appears

Ensure that the correcttables and field names

display

Make sure type isOne-To-Many

Click

Check optionsas desired



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Summary


Join line is thick at both ends if referential integrity option has been chosen

Save theRelationshipby clicking the Save button

in the Quick Access toolbar

Join line

This join line shows that each client may have many claims (1 to ∞)



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Summary

Specifying Referential IntegritySpecifying Referential Integrity

If a related table contains a record,

you will not be able to change or deletea primary key value

inthe primary table

As you change a primary key value in the

primary table, Accesswill automatically updatethe matching value in the

related tables

As you delete a record

in the primary table, Access will also

delete any related records in the related

tables



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Summary

Printing Database RelationshipsPrinting Database Relationships

With the Relationships open, click the Relationship Report button

The Relationships report in Print Preview

Click the Print button in Quick Access toolbar



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Summary

Creating Additional RelationshipsCreating Additional Relationships

Open Relationships if necessary and click the Show Table button to add other tables to the database relationships

Drag a primary key in one table to a foreign key in another table

Follow the same procedure as before to verify the table fields and

the relationship type, and to set the

desired referential integrity



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Summary

Editing a RelationshipEditing a Relationship

Right-click a join lineand click

Edit RelationshipOROR

Can move a table entry by dragging its Title bar

Open Relationships …

Click a join line and click

ORORDouble-

click a join line



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Summary

Deleting a RelationshipDeleting a Relationship

Open Relationships …

Right-click a join lineand click Delete

ORORClick a join line and press the Delete key



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Summary

Showing a SubdatasheetShowing a Subdatasheet

Click + signpreceding

desired record+ expands- collapses

Select tableClick OK



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Summary

Displaying Related Records in a SubdatasheetDisplaying Related Records in a Subdatasheet

Can view, edit or add data in the

subdatasheet

Click + signpreceding

desired record+ expands- collapses

Only available when tables have relationships



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Summary

Managing SubdatasheetsManaging Subdatasheets

Can choose a different

subdatasheet

With an open table …Click Home tab, More button

(in the Records group)

Can remove the

subdatasheet

Same as clicking the + or – preceding each record of the

table



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OBJECTIVES






Summary

How do you identify a primary key?

Features Summary

Image of a key shows by the field name



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Summary

How do you display the Relationships window?

Database Tools tab,Relationshipsbutton

Features Summary



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Summary

How do you display the Edit Relationships dialog box?

Features Summary

Right-click a join lineand click

Edit RelationshipORORClick a

join line and click

OROR Double-click a join

line



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OBJECTIVES






Summary

How do you display the Show Table dialog box?

Database Tools tab, Relationships,click the Show Table button

Features Summary



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Summary

How do you print database relationships?

With the Relationships open, click the Relationship Report button

Click the Print button in Quick Access toolbar

Features Summary



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Summary

How do you display the Insert Subdatasheet dialog box?

Features SummaryFeatures Summary

Click the + signpreceding a record

Click Home tab, Records group, More

button,Click

Open a tableOR

Features Summary



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Summary

Coming NextComing Next

MODIFYING AND MANAGING TABLES

Chapter 3Chapter 3

Technology

Access07 l1 ch2