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 command to get data from Microsoft Office Excel Create and modify a multiple-table select query.

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 R 1 and R 2 ; ii) The attributes in FK in R 1 have the same domain(s) as the primary key attributes PK in R 2 ; the attributes FK are said to reference or refer to the relation R 2.

Referential integrity A value of FK in a tuple (record) t 1 of the current state r(R 1 ) either occurs as a value of PK for some tuple t 2 in the current state r(R 2 ) or is null. In the former case, we have t 1 [FK] = t 2 [PK], and we say that the tuple t 1 references or refers to the tuple t 2. 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 Relationship between 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 from drop-down menu

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

SELECT Consultants.Lastname, Consultants.Status, Clients.Lastname, Clients.CountType, Clients.Assets FROM Consultants, Clients WHERE Consultant.ConsultantID = Clients.ConsultantID GROUP 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

Referential Integrity Delete Record button Click + to display related 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 = ‘ ’ and pno = 10. When deleting, the referential constraint will be checked. - The following deletion is not acceptable: Delete the EMPLOYEE tuple with ssn = ‘ ’ - 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 Pno null   This violates the entity constraint. 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 X axis now match the 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 the database 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 button corresponds to 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 user interface (Switchboard) Convert Database command changes an Access 2000 file to a previous version Compact and Repair Database command

Practice with Access 1. The Client Master List 2. The HMO Database 3. Creating a Switchboard 4. The Look Ahead Databas 5. Linking Versus Importing 6. Pivot Tables 7. Pivot Charts

Case Studies Your First Consultant’s Job The Wellness Center The Database Wizard Compacting Versus Compressing