1. Introduction to Management Information Systems Chapter 4 Database Processing
HTM 304
Fall 07

2. Learning Objectives Know purpose of database processing
List components of a database system
Understand important database terms
Know elements of the entity-relationship model
Understand general nature of database design

3. Purpose of a Database
Keep track of things
with more than one theme

4. One Theme Spread Sheet

5. Multi-theme Database All three records for one student
(student is the link of different themes)
Student
Score
records
office
visits

6. Database Hierarchy Bytes: the basic elements which compose of database
Fields (Columns). Name, number or characters that describe an aspect of a business object or activity.
e.g. Student Numbers, Student Names, Midterm Scores, etc.
Record (Rows). Collection of related data fields.
e.g Jenny White 89.
File (or Table). Collection of related records.
e.g. Student Score Table, Student Office Visit Table, Student Record Table
Database. Collection of integrated and related files + Relations between (among) tables + structure of data.
The relations and structures are called metadata

7. Components of Database
Tables or Files +
Relationships among Rows in Table
Metadata
Database =
How to effectively organize and process raw data is the key to a successful database design and an Information System design.

8. Student Table
Records/Rows
Columns/Fields

9. Poorly Designed Table Pros and cons? Common Practice in Excel
In Database Design, the record will be split into 2 records:
Jones Feb 1, Finance
Jones Feb 1, Accounting
Pros and cons?

10. Relationships
The records in different tables are connected by certain relationships – relational databases
Key – column or group of columns that identifies a unique row in a table
For example: Student Number is key of Student table
The key insures no repeated records
Every table MUST have a key
Foreign key – non-key column or field in one table that links to a primary key in another table
Student Number in and Office_Visit tables
Foreign keys link records from different tables together as one compound record

11. Examples of Relationships
Foreign Key
Key
Foreign Key

12. Relationships among Rows
Review Components
Tables or Files +
Relationships among Rows
Metadata
Database =

13. Metadata
Metadata are data that describe data (Format, Field Properties, etc.)
Makes databases much more useful
No one needs to guess, remember, or record what is in database
Make databases easy to use for authorized and unauthorized purposes

14. Exercise: Use Access to setup a data table
Create a database file (*.mdb)
Create table in design view
All tables are in one database file
First create the table in design view
Specify the fields (column headers)
Specify the types of the fields, and other properties
Specify which field is the key!
Finish design view -- Close the design view
Fill in records in the table
Double click the table to enter editing view
Enter records
Try enter repeated keys, it won’t let you! Why?
Use Student Visit example

15. DB Application Systems Components
Pure database data correct, but raw form not pertinent or useful
DB applications make DB data accessible and useful
Users employ DB applications
Forms
Formatted reports
Queries (SQL language)
Application programs
Each calls on DBMS to process DB tables

16. DB Application System Components
DBMS (Database Management System)
A program used to create, process, and
administer a database.
Database developers use the DBMS to
create tables, relationships, and other
structures in the database.

17. Enterprise DBMS Process large organizational and workgroup databases
Support many, perhaps thousands, of users and many different database applications
Support 24/7 operations and can manage dozens of different magnetic disks with hundreds of gigabytes or more data
IBM’s DB2, Microsoft’s SQL Server, and Oracle are examples of enterprise DBMS products

18. Personal DBMS Designed for smaller, simpler database applications.
Used for personal or small workgroup applications that involve <100 users, normally fewer than 15
Bulk of personal databases have only a single user
Microsoft Access only available personal DBMS

19. Language used in DBMS SQL: Structured Query Language
An international standard language for processing a database: Data Manipulation/Definition and Data Queries
Data Manipulation
Data Queries: See later.
INSERT INTO StudentTable ([Student Number], [Student Name], Hw1, Hw2, MidTerm) VALUES (1000, ‘Joe Black’, 90, 85, 88)
UPDATE StudentTable SET MidTerm = ’90’ WHERE Student Number = ‘1000’
DELETE FROM StudentTable WHERE MidTerm = NULL

20. Exercise: Below shows the original table.
Write down the resulting table after executing the following SQL command:
UPDATE StudentTable SET LetterScore = ’A’ WHERE Score >= ‘90’.
Original Table: StudentTable
StudentNumber
StudentName
Score
LetterScore
1000
Justin Frank 89 --
2000
Dennis Wilson 60
3000
Sheldon Benson 92
4000
Gordon Black 87
5000
Jimmy Foxx 96
Exercise: write down all the other letter scores based on certain criterion.

21. DB Application System Components
D B M S
Database Applications: collection of forms, reports, queries, and application programs that process a database.
A database may have one or more applications, and each app. may have one ore more users…(Page 84)
DBMS (Database Management System)
A program used to create, process, and
administer a database.
Database developers use the DBMS to
create tables, relationships, and other
structures in the database.

22. Multiple Database Applications
Think how the school uses student information?

23. Form – A structured way to edit and view data

24. Example Student Report
Read Only. No Editing

25. Query
Use SQL to search through the database and produce certain results.
SELECT (certain attributes) FROM (certain database tables)
WHERE (conditions)
SELECT STUDENT Name, MIDTERM
FROM STUDENTTABLE
WHERE MIDTERM>90

26. Exercise:
Write down the results when using the following query command on the following original data table:
SELECT MIDTERM FROM STUDENTTABLE WHERE MIDTERM>90
SELECT Student Name FROM STUDENTTABLE WHERE MIDTERM<70
SELECT Student Name, Student Number, HW1, HW2, MidTerm FROM STUDENTTABLE WHERE MidTerm > (HW1+HW2)/2

27. DB Application System Components

28. Database Development Process
E-R Modeling: High level blueprint
defining how data are stored
structurally in the system
Define users’ need
through interview

29. E-R Modeling
E-R Model: a detailed, logical representation of the data for a business. To document rules and policies of an organization that govern data.

30. Components in E-R Model
Entity – something users want to track
Examples Order, Customer, Salesperson, Item
Some entities represent physical object, such as an Item or Salesperson
Other entities represent a logical construct of transaction, such as Order or Contact
Entities have attributes that describe characteristics of the entity
Example attributes of Salesperson are SalespersonName, , Phone, etc.

31. Entities (cont)
Entities have identifier, an attribute (or group of attributes) whose value is associated with 1 & only 1 entity instance
OrderNumber is the identifier of Order, because only 1 Order instance has given value of OrderNumber
CustomerNumber identifier of Customer
If each member of sales staff has unique
name, then SalespersonName is an identifier of Salesperson

32. Student Data Model Entities

33. Relationships Connects identities, allow cross entity search
A line is used to represent a relationship between two entities

34. Three basic types of relationships
One-to-one:
One student can buy only one permit
One permit can only
purchased by one student
One-to-Many:
One instructor can teach many courses
A course can only be taught by one instructor
Crow’s foot = Many
Many-to-Many:
One student can take more than one course
A course can be registered by multiple students
Parking Permit #
Date of Purchase
Type of Permit
Expiration Date …
Student ID
Name
DoB
Address
Student
Parking permit
CRN
Course Title
Classroom
Credit …
Instructor ID
Name
Department
Office
instructor
Course
CRN
Course Title
Classroom
Credit …
Student ID
Name
DoB
Address
Student
Course

35. Who defines the relationships?
Exercise
Who defines the relationships?

36. Exercise:
Exercise 22 a) (Page 105)

37. Opposing Forces Guide:
No, Thanks, I’ll Use a Spreadsheet
I’m not buying all this stuff about databases.
“I’ve tried them and they’re a pain-way too complicated to set up, and most of the time, a spreadsheet works just as well.”
“No, unless you are a General Motors or Toyota, I wouldn’t mess with a database.”
“You have to have professional IS people to create it and keep it running.”
“Besides, I don’t really want to share my data with anyone.”
“I work pretty hard to develop my client list.”
“Why would I want to give it away?”
“When I want something, I use Excel’s Data Filter.”
“I can usually get what I need.”
“Of course, I can’t still send form letters, but it really doesn’t matter.”
“I get most of my sales using the phone, anyway.”

38. Database Security
The firewall, a computing device located between a firm’s internal network and external networks, prevents unauthorized access to the internal network.
For the best security, the DBMS computer should be protected by a firewall, and then all other security measures should be designed as if the firewall has been breached.

39. Database Security (cont)
All operating systems and DBMS patches should be installed as soon as they become available.
No one other than authorized operations personnel should be able to directly access the computer that runs the DBMS.
The computer running the DBMS should be secured behind locked doors, and visits to that room should be recorded in a log.
Most DBMS products log failed attempts to sign on and produce other usage reports as well.
The database administrator (DBA) should periodically monitor such logs and reports for suspicious activity.

40. Database Security (cont)
All major DBMS products have extensive, built-in security features.
These features allow for the definition of user accounts and user roles.
Each user account belongs to a specific person.
A role is a generic employee function, such as payroll clerk or field salesperson.
Once an account is defined, it can be assigned specific permissions, and it can also be assigned particular roles.
It is important to have a plan of action for security emergencies.
Disaster Recovery Plan (85%)
Business Continuity Plan (<15%)
The steps to be taken vary from database to database.

41. Ethic Guide: Nobody Said I Shouldn’t
Kelly make a backup copy of his company’s database on CD and took it home and installed it on his home computer.
While performing queries on the database, he found customer order information and focused in on his friend Jason’s customer order entries.
Kelly noticed that Jason gave huge discounts to Valley Appliances but not to his other customers.
At an after work gathering, Kelly asked Jason about the Valley Appliances discount telling him what he had been doing.
When Kelly returned to work, he was fired

42. Class 2: E-R Modeling and Database Lab
E-R Data Model
The most popular technique for creating a data model.
E: entity (things)
R: relationship (among the entities)
+ business rules restricting the flow of the data
Data Model:
Read Problem Solving Guide: (p89a)
Immanuel Kant, Data Modeler
Attempts to model the “real world”
Simply a model of what the data modeler perceives

43. 5 minutes free write Social Implications of DB:
Relate any of Kant’s ideas to what you learned from reading “For Some, Online Persona Undermines Resume”
PRINT your name on Free Write and hand it in

44. More exercise
Book 23 a) Create a E-R Diagram to relate all the information in the form

45. Translating E-R diagram into Tables (1:N)
Key
Step 1: Create
one table for
each entity
Key

46. Translating E-R diagram into Tables (1:N)
Step 2: Add Foreign Key Column to the “many entity” to represent relationship

47. Step 3: edit relationship
Go to Tools  Relationships
Add two entities
Drag the “advisor name” of advisor table to the “advisor name” of student table.
Close relationships

48. Many-to-Many Relationship
Now the rule changed
One advisor can supervise many students
One student can have many adviser
One student must have at least one advisor
One advisor can have no student

49. Foreign Key doesn’t work for N:M relationship

50. Solution

51. Exercise:
Revise the relationship of previous exercise in Access and input the above records

52. 1:1 Relationship
How to convert into tables?

53. Exercise
Based on your E-R diagram in 23(a), construct tables and relationships in Access. Add at least three records for each table.

54. Importance of User Review
Users are the final judges of what data the database should contain and how records relate to one another
Easiest time to change database structure is during data modeling stage
Once database has been constructed, loaded with data, and application forms, reports, queries, and application programs created, changing a relationship means weeks of work!

55. How should you review as a user? (Cont)
When database developed for your use, you must carefully review data model
If you don’t understand any aspect of it, ask for clarification until you do
Data model must accurately reflect your view of business
Do not proceed unless you are 100% comfortable with the model

56. Key Terms and Concepts Access Field File (Table) Attribute Foreign key
Byte
Foreign key
Column
Identifier
Crow’s foot
Key
Database
Maximum cardinality
Database application system
Meta Data
DBMS
Minimum cardinality
E-R data model
1:N(one-to-many) relationship

57. Key Terms and Concepts (Cont.)
Access
Field
many-to-many relationship
Attribute
File (Table)
Oracle
Byte
Foreign key
Query
Column
Identifier
Personal DBMS
Crow’s foot
Key
Record
Database
Maximum cardinality
Relationship
Database application system
Meta Data
Report
DBMS
Minimum cardinality
Row
E-R data model
one-to-many relationship
SQL Server