Exploring Microsoft Access 2003

Chapter 4 Proficiency:

Relational Databases, External Data,

Charts, Pivot, and the Switchboard

Objectives (1 of 2)

• Describe one-to-many relationships

• Create a one-to-many relationship

• Use the Get External Data commandto get data from Microsoft Office Excel

• Create and modify a multiple-table selectquery.

Objectives (2 of 2)

• Use aggregate functions to create a totals query• Use Microsoft graph to create a chart based on

a table or query• Use the Switchboard Manager to create and/or

modify a switchboard

Overview

• Share data between Microsoft Office applications

• Display data from two tables in one query• Total query aggregates results from groups

of records to create summary information• Create Chart and Pivot• Create a user interface

Multiple-Table Queries

• One-to-many relationship• Primary key (PK)• Foreign key (FK)

i) Consider two relation schemas R1 and R2;

ii) The attributes in FK in R1 have the same domain(s) as the primary key attributes PK in R2; the attributes FK are said to reference or refer to the relation R2.

• Referential integrity

A value of FK in a tuple (record) t1 of the current state r(R1) either occurs as a value of PK for some tuple t2 in the current state r(R2) or is null. In the former case, we have t1[FK] = t2[PK], and we say that the tuple t1 references or refers to the tuple t2.

Example:

Employee(SSN, …, Dno) Dept(Dno, … )

FK

Get External Data

• Get External Data command

• Export command

• Import Spreadsheet Wizard

• Import Text Wizard

• Importing versus linking

Importing & Exporting

Hands-On Exercise 1• Open the Investment Database• Import Spreadsheet Wizard• Create the Relationship• Print the Relationship• Add the New Data• Create & Complete the Multiple-Table Query• Export the Query and Modified Tables• View the Excel Workbook

Multiple Table Query

Relationshipbetween tables

Each field &table to display

Total Queries

A total query

• Summary functions• Total row• Group By• Count function• Sum function

Total Queries & Charts

Hands-On Exercise 2

• Copy Assets Under Management Query• Create a Total Query• Check Your Progress• Start the Chart Wizard• Complete the Chart Wizard• Increase the Plot Area• Change the Data

Total Query

Run button

Select Count fromdrop-down menu

SELECT Consultants.Lastname, Count(Clients.LastName), Sum(Assets)FROM Consultants, ClientsWHERE Consultant.ConsultantID = Clients.ConsultantIDGROUP BY Consultants.Lastname

SELECT Consultants.Lastname, Consultants.Status, Clients.Lastname, Clients.CountType, Clients.Assets

FROM Consultants, ClientsWHERE Consultant.ConsultantID = Clients.ConsultantIDGROUP BY Consultants.Lastname

The results are grouped according to the last name of the consultants.The records with the same last name are in the same group.

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5

1

5

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Referential Integrity

Delete Record button

Click + to displayrelated records

You cannot delete a Consultant without first deleting related Clients

fname, minit, lname, ssn, bdate, address, sex, salary, superssn, dno

Dname, dnumber, mgrssn, mgrstartdate

Dnumber, dlocation

Pname, pnumber, plocation, dnum

Essn, pno, hours

Essn, dependentname, sex, bdate, relationship

EMPLOYEE

DEPARTMENT

DEPT _LOCATIONS

WORKS_ON

PROJECT

DEPENDENT

Updating and constraints

delete

•Delete the WORK_ON tuple with Essn = ‘999887777’ and pno = 10.

•When deleting, the referential constraint will be checked.

- The following deletion is not acceptable:

Delete the EMPLOYEE tuple with ssn = ‘999887777’

- reject, cascade, modify (cascade update)

Cascade delete – a strategy to enforce referential integrity

ssn

Employee

Essn Pno

delete

Works-on

delete

Cascade delete – a strategy to enforce referential integrity

Employee

delete

ssn supervisor

null

Employee

delete

ssn supervisor

null

delete

not reasonable

Modify – a strategy to enforce referential integrity

ssn

Employee

Essn Pno

delete

Essn Pnonull

This violates the entity constraint.

Works-on Works-on

Modify – a strategy to enforce referential integrity

ssn

Employee

delete

This does not violate the entity constraint.

Department

Dno

chairman

Department

null

Dno

chairman

Chart Wizard

View button

Modified Y and Xaxis now matchthe query data

Chart from Wizard

The User Interface

• Switchboard

• Switchboard Manager

• Switchboard Items table

Other Access Utilities

• Convert Database command

• Compact and Repair Database command

Compact the Database

View button

Select thedatabase

Click compact

The Switchboard Manager

Hands-On Exercise 3• Start the Switchboard Manager• Complete the Switchboard• Test the Switchboard• Insert the Clip Art• Complete the Design• The Completed Switchboard• Compact the Database

Switchboard Manager

Each buttoncorrespondsto a command

Chapter 4 Summary (1 of 2)

• One-to-many relationships• A query can display data from multiple

tables• Get External Data command• A total query performs calculations on• a group of records using summary

functions

Chapter 4 Summary (2 of 2)

• Switchboard Manager creates the userinterface (Switchboard)

• Convert Database command changes anAccess 2000 file to a previous version

• Compact and Repair Database command

Practice with Access

1. The Client Master List2. The HMO Database3. Creating a Switchboard4. The Look Ahead Databas5. Linking Versus Importing6. Pivot Tables7. Pivot Charts

Case Studies

• Your First Consultant’s Job

• The Wellness Center

• The Database Wizard

• Compacting Versus Compressing