Lecture Management information systems: Solving business problems with information technology – Chapter 6

Introduction to MIS
Chapter 6
Database Management Systems

Copyright © 1998-2002 by Jerry Post

Introduction to MIS

1


Database Management Systems

Reports and
ad hoc queries

Database
DBMS
Programs

Sales and transaction data

 

Introduction to MIS

 

2

Outline









 

Relational Databases
Queries
Designing a Database
Database Applications
Database Administration
Database and e-Business
Cases: Airlines
Appendix: Building Forms in Access

Introduction to MIS

 

3


DBMS & People
Database Administrator

(Standards, Design, and Control)

Programmer
Analyst

Data
Programs
& Revisions

Database
Management
System
Program

Business Needs

Ad Hoc Queries
Managers
and Reports

Program

Data Collection
and Transaction
Processing
Business Operations

 

Introduction to MIS

 

4


Relational Databases


Tables






Rows
Columns
Primary keys

Data types





Text
Dates & times
Numbers
Objects

Customer Table
Phone
312-555-1234
502-555-8876
602-555-9987
612-555-4325

Name
Jones
Smith
Juarez
Olsen

Introduction to MIS

 

City
Chicago
Glasgow
Phoenix
Minneapolis

Orders Table
Customer
502-555-8876
602-555-9987
612-555-4325
502-555-8876

 

Address
123 Main
456 Oak
887 Ribera
465 Thor

Date
3/3/04
4/4/04
4/9/04
5/7/04

Salesperson
2223
8876
8876
3345

Total_sale
157.92
295.53
132.94
183.67

5

Programming Approach


Problems with Programming






Data and programs
Undocumented files
Files & many programs
Multiuser
Changes

file 1
Invoice
Program

customers

Billing
Program

file A

file B

 

Introduction to MIS

 

6




Focus on data














 

Accuracy.
Time.
Concurrency.

Security.

Ad hoc queries
Speed of development




Change programs without
altering data.

Data integrity




Database Advantages

Data independence




Stable data
Programs change.

Report writers.
Input forms.
Data manipulation.

All Data Files
Database Management
System
Invoice
Program

Billing
Program

Flexibility & Queries

Introduction to MIS

 

7


Database Queries




Single Table
Computations
Joining Tables

Four questions to create a query
1)
2)

3)
4)

 

Introduction to MIS

 

What output do you want to see?
What tables are involved?
What do you already know? (constraints)
How are the tables joined?

8


File: C05E15a.mdb

Single Table Query Introduction
Sample Data

CID
28764
87535
44453
29587

Name
Adamz

James
Kolke
Smitz

Phone
602-999-2539
305-777-2235
303-888-8876
206-676-7763

City
Phoenix
Miami
Denver
Seattle

AccountBalance
197.54
255.93
863.39
353.76

Query: Which customers have balances greater than $200?
Access Query Screen (QBE)

 

Introduction to MIS

 

9


“AND” Conditions and Sorting

Sample Data
CID
28764
87535
44453
29587

Name
Adamz
James
Kolke
Smitz

Phone
602-999-2539
305-777-2235
303-888-8876
206-676-7763

City
Phoenix
Miami
Denver
Seattle

AccountBalance
197.54
255.93
863.39
353.76

Query: Which Denver customers have balances greater than $200?
Access Query Screen (QBE)

 

Introduction to MIS

 

10


SQL Introduction
CID
28764
87535
44453
29587

Name
Adamz
James
Kolke

Smitz

Phone
602-999-2539
305-777-2235
303-888-8876
206-676-7763

City
Phoenix
Miami
Denver
Seattle

AccountBalance
197.54
255.93
863.39
353.76

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

SELECT CID, Name, Phone, City, AccountBalance
FROM
Customers
WHERE AccountBalance > 200 ;

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

 

SELECT CID, City, AccountBalancel
FROM
Customers
WHERE AccountBalance > 200 and City = “Denver”
ORDER BY Name ASC ;

Introduction to MIS

 

11


Useful WHERE Conditions


Comparisons



Numbers
Text








<, =, >, <>, BETWEEN
AccountBalance > 200
Name > “Jones”

Common
LIKE


Match all



Match one

Dates

Name LIKE “J*”
Name LIKE “?m*”

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

Missing data
NOT

City is NULL
Name is NOT NULL

Use with QBE or SQL

 

Introduction to MIS

 

12


SQL General Form







 

SELECT
FROM
JOIN
WHERE
GROUP BY
ORDER BY

Introduction to MIS

columns
tables

link columns
conditions
column
column (ASC | DESC)

 

13










 

Sum
Avg
Min
Max
Count
StDev
Var

Introduction to MIS

SQL

Computations

SELECT Count(C#), AVG(AccountBalance)
FROM
Customers ;

QBE

 

14


Groups or Subtotals

QBE

Sample Output
SQL
SELECT
FROM
GROUP BY

 

Introduction to MIS

City, AVG(AccountBalance)

Customers
City ;

 

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

15


Groups with Conditions

Query: What is the average account balance for customers from Denver?

 

Introduction to MIS

 

16


Multiple Tables
Customers
CID
12345
28764
29587
44453
87535

Name
Jones
Adams
Smitz
Kolke
James

Phone
312-555-1234
602-999-2539
206-656-7763
303-888-8876
305-777-2235

City
Chicago
Phoenix

Seattle
Denver
Miami

AccountBalance
$197.54
$526.76
$353.76
$863.39
$255.98

Salespeople
SID
225
452
554
663
887

Name DateHired
West
5/23/75
Zeke
8/15/94
Jabbar 7/15/91
Bird
9/12/93
Johnson 2/2/92

Phone

Commission
213-333-2345
5
213-343-5553
3
213-534-8876
4
213-225-3335
4
213-887-6635
4

Orders
OrderID CID
117
12345
125
87535
157
12345
169
29587
178
44453
188
29587
201
12345
211
44453

213
44453
215
87535
280
28764

SID
887
663
554
255
663
554
887
255
255
887
663

Odate
3/3/2004
4/4/2004
4/9/2004
5/5/2004
5/1/2004
5/8/2004
5/28/2004
6/9/2004
6/9/2004

6/9/2004
5/27/2004

Amount
$57.92
$123.54
$297.89
$89.93
$154.89
$325.46
$193.58
$201.39
$154.15
$563.27
$255.32

ItemsSold
Items
ItemID
1154
2254
3342
7653
8763
9987

 

Description
Corn Broom

Blue Jeans
Paper Towels--3 rolls
Laundry Detergent
Men's Boots
Candy Popcorn

Introduction to MIS

 

Price
$1.00
$12.00
$1.00
$2.00
$15.00
$0.50

OID
117
117
117
125
125
157
169
169
178

ItemID

1154
3342
7653
1154
8763
7653
3342
9987
2254

Quantity
2
1
4
4
3
2
1
5
1

17


Linking Tables

The Orders to ItemsSold relationship enforces referential integrity.
One Order can list many ItemsSold.

 

Introduction to MIS

 

18


Query Example


Which customers (CID) have placed
orders since June 1, 2004?

QBE
SQL
SELECT CID, ODate
FROM
Orders
WHERE Odate >= #6/1/2004# ;

CID
44453
44453
87535
28764

 

ODate

6/9/2004
6/9/2004
6/9/2004
6/27/2004

Introduction to MIS

 

Results

19


Query Example


What are the names of the customers who placed orders since June 1,
2004?
QBE
SQL
SELECT DISTINCT Name, Odate
FROM
Orders
INNER JOIN Customers ON
Orders.CID = Customers.CID
WHERE Odate >= #6/1/2004# ;

Name
Adamz

James
Kolke

 

Odate
6/27/2004
6/9/2004
6/9/2004

Introduction to MIS

 

Results

20




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

Query Example

SQL
SELECT DISTINCT Salespeople.Name,
Customers.Name

FROM
Salespeople INNER JOIN (Customers INNER JOIN Orders ON
Customers.CID=Orders.CID) ON Salespeople.SID = Orders.SID
ORDER BY Salespeople.Name ;
Results

SalesName Cust.Name
Bird
Adamz
Bird
James
Bird
Kolke
Jabbar
Jones
Jabbar
Smitz
Johnson
James
Johnson
Jones
West
Kolke
West
Smitz

 

Introduction to MIS

QBE

 

21


Aggregation Query


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

QBE

Results

$2,418.84

SQL

 

SELECT SUM(Amount)
FROM
Orders
INNER JOIN Customers ON Orders.CID = Customers.CID
WHERE City = “Miami” ;

Introduction to MIS

 

22






Primary keys
One value per cell
Column depends on whole
key and nothing but the key.

Database Design

Customers
CID
11
22
33
44

name
Jones
Smith
James
Ricci

city
Chicago
Chicago
Chicago
Chicago

home
business
111-1111 222-2222
111-4567
111-2567 222-8976

fax
222-35534

service
876-3456
444-5353

333-8765

Phones(CID, phone_type, number)
Customers(CID, name, city)
CID
11
22
33
44

 

Introduction to MIS

name
Jones
Smith
James
Ricci

 

city
Chicago
Chicago
Chicago
Chicago

CID
11
11
11
11
22
22
33
44

phone_type
home
business

fax
service
home
service
home
fax

number
111-1111
222-2222
222-3534
876-3456
111-4587
444-5353
111-2567
333-8765

23


File: C05Vid.mdb

Database Design: Normalization

 

Introduction to MIS

 

24


Notation
Table
columns

Table
name

Customer (CustomerID, Phone, Name, Address, City, State, ZipCode)
Primary key is
underlined
CustomerID
1
2
3
4
5
6
7
8
9
10

 

Phone
502-666-7777
502-888-6464

502-777-7575
502-333-9494
502-474-4746
615-373-4746
615-888-4474
615-452-1162
502-222-4351
502-444-2512

Introduction to MIS

LastName
Johnson
Smith
Washington
Adams
Rabitz
Steinmetz
Lasater
Jones
Chavez
Rojo

 

FirstName
Martha
Jack
Elroy
Samuel

Victor
Susan
Les
Charlie
Juan
Maria

Address
125 Main Street
873 Elm Street
95 Easy Street
746 Brown Drive
645 White Avenue
15 Speedway Drive
67 S. Ray Drive
867 Lakeside Drive
673 Industry Blvd.
88 Main Street

City
Alvaton
Bowling Green
Smith's Grove
Alvaton
Bowling Green
Portland
Portland
Castalian Springs
Caneyville
Cave City

State
KY
KY
KY
KY
KY
TN
TN
TN
KY
KY

ZipCode
42122
42101
42171
42122
42102
37148
37148
37031
42721
42127

25