1. Chapter 9 Database Management

2. Today Review 6 parts of the IT model Understand what a database is
Demonstrate a database example using Access

3. Definitions:
Data – a collection of unprocessed items which can include text, numbers, images, audio, and video.
Database – a collection of related data organized in a manner that allows users to keep track of that data.
Database software (DBMS) – software that allows users to create a digital database.

4. Think about it Name the data that would need to be kept track of in…
A telephone directory,
College course offerings,
Members of Congress,
Movie listing,
Party guest list?

5. Databases, Data and Information
What is a database?
Collection of data organized so you can access, retrieve, and use it
Database software allows you to
Database software also called database management system (DBMS)
Create forms and reports
Create database
Add, change, and delete data
Sort and retrieve data
p. 332
Next

6. The Hierarchy of Data bit byte field record file DB
Bit=smallest unit of data a computer can understand
Character = 1 Byte or 8 bits
Field = a collection of related characters
Records = a collection of related fields
Data Files (Tables) = a collection of related records
Database = a collection of related files
bit
byte
field
record
file DB

7. The Hierarchy of Data What is a field?
Combination of one or more characters
Smallest unit of data user accesses
Field size defines the maximum number of characters a field can contain
Field name uniquely identifies each field
Data type specifies kind of data field contains
p. 335 Fig. 9-3
Next

8. The Hierarchy of Data What are common data (field) types? Text Numeric
(also called alphanumeric)—letters, numbers, or special characters
Numeric
numbers only
AutoNumber
unique number automatically assigned to each new record
Currency
dollar and cent amounts or numbers containing decimal values
Date
month, day, year, and sometimes time
Memo
lengthy text entries
Object
photograph, audio, video, or document created in other application such as word processing or spreadsheet
Yes/No
only the values Yes or No (or True or False)
Hyperlink
Web address that links to document or Web page
p. 335
Next

9. Consider the following DB examples:
Personnel files
Customer purchases
Student records
Course offerings
Cookbook
Party guest list
What field names would you expect to find in each DB?

10. The Hierarchy of Data What is a record? Group of related fields
Key field, or primary key, uniquely identifies each record
p. 336
Next

11. Name the unique identifiers…
United states citizen
Mercer student
Person using computer
Cell phone
user
Web site
Web page
Computer connected to the Internet
Social security number
Student ID
User name
Phone number
address
Domain name
URL
IP address

12. The Hierarchy of Data What is a data file?
Collection of related records stored on disk
key field
records
fields
22 Fifth Avenue
P.O. Box 45
15 Duluth Street
33099 Clark Street
1029 Wolf Avenue
Address
Auburn
Clanton
Prattville
Montgomery
City AL
Weinberg
Jonah
3928
Marcus
4872
Valesquez
Adrian
3376
Murray
Shannon
2928
Vandenberg
Donna
2295
State
Last Name
First Name
Member ID
Green
p. 336
Next

13. Maintaining Data What is file maintenance?
Procedures that keep data current
Adding records
Changing records
Deleting records
The DBMS makes file maintenance possible
p. 336
Next

14. Database Management Systems
What are popular database management systems (DBMSs)?
p. 343
Next

15. Access specifics
There are 4 DB objects that are used by Access:
Tables – all of the data is stored in tables. Tables are arranged in rows and columns.
Forms – provide an easy-to-use data entry screen.
Reports – used to create professional reports
Queries – allow users to select a subset of fields and records from one or more tables rather than having to navigate many fields and records from large DB’s.

16. Access example
Example DB

17. Discuss
California was the first state to employ a controversial database. Based on Megan’s Law — the statute named for a seven-year-old girl who was violated and killed by paroled felon — the database listed the names and addresses of people convicted of crimes against children. Today, many states employ similar databases. In some communities, when a paroled offender moves in the police inform the local school system, which in turn sends parents a notification that includes a history, address, and picture of the wrongdoer. Touted as a valuable tool in crime prevention, some feel that publishing this information makes it impossible for an offender to lead a normal life and can result in vigilantism — one paroled lawbreaker’s car was firebombed only days after his name was released.
 Should a database of people paroled or released for crimes against children be shared?
Who should have access to the database?
Should such a database include accused, but not convicted, offenders?

18. Discuss
For many students, the cost of college is even more depressing than the quality of dining hall food. A free Web service can help students find scholarships that match their qualifications, plans, and chosen schools. When a student registers, the service queries a database of more than 180,000 records in search of suitable scholarships and then returns the results. Ironically, those least likely to benefit from the scholarship search may be those who need it most. Because students from poorer backgrounds usually have less computer experience, they may be unaware of, or unable to access, the scholarship search service.
Who should assume the leading role in extending access to the service?
How can the Web service be made more universally available?