Introduction to MISIntroduction to MISChapter 5Chapter 5

Database Management Database Management SystemsSystems

Copyright 1994-1996 by Jerry PostCopyright 1994-1996 by Jerry Post

Database Management Database Management SystemsSystems

Data files

Without a DBMS:Hard to find and share data.

Strategy

Tactics

Operations

Company A

Database

DBMS

Programs

With a DBMS:Integrated data with shared access.

Strategy

Tactics

OperationsCompany B

Database AdvantagesDatabase Advantages

Focus on dataFocus on data– Stable dataStable data– Programs change.Programs change.

Data independenceData independence– Change programs Change programs

without altering data.without altering data.

Data integrityData integrity– Accuracy.Accuracy.– Time.Time.– Concurrency.Concurrency.– Security.Security.

All Data Files

Database ManagementSystem

InvoiceProgram

BillingProgram

Relational DatabasesRelational Databases

TablesTables– RowsRows– ColumnsColumns– Primary keysPrimary keys

Data typesData types– TextText– Dates & Dates &

timestimes– NumbersNumbers– ObjectsObjects

Phone Name Address City312-555-1234 Jones 123 Main Chicago502-555-8876 Smith 456 Oak Glasgow602-555-9987 Juarez 887 Ribera Phoenix612-555-4325 Olsen 465 Thor Minneapolis

Customer Table

Customer Date Salesperson Total_sale502-555-8876 3/3/95 2223 157.92602-555-9987 4/4/94 8876 295.53612-555-4325 4/9/96 8876 132.94502-555-8876 5/7/95 3345 183.67

Orders Table

Multiple TablesMultiple Tables

C# Name Phone City AccountBalance12345 Jones 312-555-1234 Chicago $197.5428764 Adams 602-999-2539 Phoenix $526.7629587 Smitz 206-656-7763 Seattle $353.7644453 Kolke 303-888-8876 Denver $863.3987535 James 305-777-2235 Miami $255.98

Customers

S# Name DateHired Phone Commission225 West 5/23/75 213-333-2345 5452 Zeke 8/15/94 213-343-5553 3554 Jabbar 7/15/91 213-534-8876 4663 Bird 9/12/93 213-225-3335 4887 Johnson 2/2/92 213-887-6635 4

Item# Description Price1154 Corn Broom $1.002254 Blue Jeans $12.003342 Paper Towels--3 rolls $1.007653 Laundry Detergent $2.008763 Men's Boots $15.009987 Candy Popcorn $0.50

O# C# S# Odate Amount117 12345 887 3/3/96 $57.92125 87535 663 4/4/96 $123.54157 12345 554 4/9/96 $297.89169 29587 255 5/5/96 $89.93178 44453 663 5/1/96 $154.89188 29587 554 5/8/96 $325.46201 12345 887 5/28/96 $193.58211 44453 255 6/9/96 $201.39213 44453 255 6/9/96 $154.15215 87535 887 6/9/96 $563.27280 28764 663 5/27/96 $255.32

O# Item# Quantity117 1154 2117 3342 1117 7653 4125 1154 4125 8763 3157 7653 2169 3342 1169 9987 5178 2254 1

Salespeople

Items

Orders

ItemsSold

Linking TablesLinking Tables

The Orders to ItemsSold relationship enforces referential integrity.

One Order can list many ItemsSold.

Database DesignDatabase Design

Primary keysPrimary keys One value per cellOne value per cell Column depends on Column depends on

whole key and whole key and nothing but the key.nothing but the key.

CustomersC# name city home business fax service11 Jones Chicago 111-1111 222-2222 222-35534 876-345622 Smith Chicago 111-4567 444-535333 James Chicago 111-2567 222-897644 Ricci Chicago 333-8765

c# name city11 Jones Chicago22 Smith Chicago33 James Chicago44 Ricci Chicago

Customers(c#, name, city)c# phone_type number11 home 111-111111 business 222-222211 fax 222-353411 service 876-345622 home 111-458722 service 444-535333 home 111-256744 fax 333-8765

Phones(c#, phone_type, number)

Database versusDatabase versus Spreadsheet Spreadsheet

Tables

Customers(C#, Name,Address)

Products(P#, Description, Price)

Sales(O#, P#, Sdate, Quantity, C#)

Part 1 SalesC# P# Q Price Price*Q SubTotal11 22 1 15.95 15.95 15.9511 35 2 5.75 11.50 27.4531 18 1 25.95 25.95 53.40

Part 2 ProductsP# Description Prices18 shorts 25.9522 shirt 15.9535 laces 4.75

Part 3 CustomersC# Name11 Smith31 Torrez

Retrieve the three tables (if they fit).

1) Select by date2) Sort By O#, P#

3) Look up prices

4) Put into Part 1

5) Calculate total

6) Sort for highest total7) Look up names

Storage v calculation Multiple tables

DBMS versus SpreadsheetDBMS versus Spreadsheet

Database QueriesDatabase Queries

Single TableSingle Table ComputationsComputations Joining TablesJoining Tables 1) What output do you want to see?

2) What tables are involved?3) What do you already know? (constraints)4) How are the tables joined?

Four questions to create a query

Single Table Query Single Table Query IntroductionIntroduction

C# Name Phone City AccountBalance28764 Adamz 602-999-2539 Phoenix 197.5487535 James 305-777-2235 Miami 255.9344453 Kolke 303-888-8876 Denver 863.3929587 Smitz 206-676-7763 Seattle 353.76

Sample Data

Query: Which customers have balances greater than $200?

Access Query Screen (QBE)

File: C05E15a.mdb

““AND” Conditions & AND” Conditions & SortingSorting

Sample Data

Query: Which Denver customers have balances greater than $200?

C# Name Phone City AccountBalance28764 Adamz 602-999-2539 Phoenix 197.5487535 James 305-777-2235 Miami 255.9344453 Kolke 303-888-8876 Denver 863.3929587 Smitz 206-676-7763 Seattle 353.76

Access Query Screen (QBE)

Useful WHERE ConditionsUseful WHERE Conditions

ComparisonsComparisons <, =, >, <>, BETWEEN<, =, >, <>, BETWEEN

– NumbersNumbers AccountBalance > 200AccountBalance > 200– TextText

CommonCommon Name > “Jones”Name > “Jones” LIKELIKE

– Match allMatch all Name LIKE “J*”Name LIKE “J*”– Match one Match one Name LIKE “?m*”Name LIKE “?m*”

– DatesDates Odate between #8/15/95# and Odate between #8/15/95# and #8/31/95##8/31/95#

Missing dataMissing data City is NULLCity is NULL NOTNOT Name is NOT NULLName is NOT NULL

ComputationsComputations

SumSum AvgAvg MinMin MaxMax CountCount StDevStDev VarVar

QBE

Groups or SubtotalsGroups or Subtotals

QBE

City AVG(AccountBalance)Chicago 197.54Denver 863.39Miami 255.93Phoenix 526.76Seattle 353.76

Sample Output

Query ExampleQuery Example

Which customers (c#) have placed orders since June 1, 1996?Which customers (c#) have placed orders since June 1, 1996?

QBE

Results

C# Odate44453 6/9/9644453 6/9/9687535 6/9/9628764 6/27/96

Query ExampleQuery Example

What are the What are the names of the names of the customers who customers who placed orders placed orders since June 1, since June 1, 1996?1996?

QBE

Results

Name OdateAdamz 6/27/96James 6/9/96Kolke 6/9/96

Query ExampleQuery Example

List the salespeople (sorted alphabetically) along with the List the salespeople (sorted alphabetically) along with the names of customers who placed orders with that salesperson.names of customers who placed orders with that salesperson.

QBE

Results

SalesName Cust.NameBird AdamzBird JamesBird KolkeJabbar JonesJabbar SmitzJohnson JamesJohnson JonesWest KolkeWest Smitz

Aggregation QueryAggregation Query

What is the total amount of orders placed from customers who live What is the total amount of orders placed from customers who live in Miami?in Miami?

QBE Results

$686.81

DBMS & PeopleDBMS & People

Data

Database ManagementSystem

Program Program

Business Operations

Ad Hoc Queriesand Reports

ProgrammerAnalyst

Database Administrator

Business Needs

Programs& Revisions

Managers

(Standards, Design & Control)

Data Collectionand TransactionProcessing

Database AdministrationDatabase Administration

Database AdministratorDatabase Administrator– TestingTesting– BackupBackup– RecoveryRecovery– StandardsStandards– Access ControlsAccess Controls

DBMS Input ScreenDBMS Input ScreenText/Labels Data Variables

Scrolling Region/Subform

CommandButtons

Record Selectors - Subform - Main

DBMS Report WriterDBMS Report Writer

Report headerReport header Page headerPage header Break/Group headerBreak/Group header DetailDetail FootersFooters

Sample Report with Sample Report with GroupsGroups

Designing Menus for UsersDesigning Menus for Users

1. Setup Choices2. Data Input3. Print Reports4. DOS Utilities5. Backups

Main Menu

Daily Sales ReportsFriday Sales MeetingMonthly Customer Letters

Quit

Customer Information

Which menu is easier to understand?

ObjectsObjects

Hypertext & Massive textHypertext & Massive text Pictures & GraphsPictures & Graphs ObjectsObjects

– VideoVideo– SoundSound– User definedUser defined

Sample OO Sample OO DatabaseDatabase

Patient X-Rays/Images ID

DateTechnician

Comments

Patient Data IDName Address DoB

Medical History

photo Patient VisitsID Date

PhysicianProblems Comments

Patient TreatmentsID Date Procedure Doctor

Massive TextMassive Text

Commercial Commercial DatabasesDatabases

CD-ROMCD-ROM Search StrategiesSearch Strategies

– KeywordsKeywords– Narrow it downNarrow it down– Boolean searchesBoolean searches

Weights (Weights (Verity Verity Topic)Topic)

Smart searchers Smart searchers

Sample Boolean searches:

Colombia

Terrorism

Medellin and (terrorist orterrorism or bombing or kidnap)