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© 2008 Prentice-Hall, Inc. Slide 1 Tomorrow’s Technology and You 8/e Chapter 7 Database Applications

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Tomorrow’s Technology and You 8/e. Chapter 7 Database Applications. Tomorrow’s Technology and You 8/e Chapter 7 Objectives. Explain what a database is and describe its basic structure. Identify the kinds of problems that can be best solved with database software. - PowerPoint PPT Presentation

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© 2008 Prentice-Hall, Inc. Slide 1

Tomorrow’s Technology and You 8/e

Chapter 7

Database Applications

© 2008 Prentice-Hall, Inc. Slide 2

Tomorrow’s Technology and You 8/e Chapter 7Objectives

Explain what a database is and describe its basic structure.

Identify the kinds of problems that can be best solved with database software.

Describe different kinds of database software, from simple file managers to complex relational databases.

© 2008 Prentice-Hall, Inc. Slide 3

Tomorrow’s Technology and You 8/e Chapter 7

Objectives (continued)

Describe database operations for storing, sorting, updating, querying, and summarizing information.

Give examples of ways in which large, easily accessible databases make lives safer or more convenient.

© 2008 Prentice-Hall, Inc. Slide 4

Tomorrow’s Technology and You 8/e Chapter 7

The Google Guys Search for Success

Google is one of the most successful companies on WWW. Search for Web pages, facts, quotes, etc. 200 million queries a day Tremendous database of material, but not organized

Launched by a Sergey Brin and Larry Page (Stanford Ph.D. students)

New approach in search technology Marks a page’s relevance by the number of times other related

web pages link to it, not how often a word or phrase appeared on a page

© 2008 Prentice-Hall, Inc. Slide 5

Tomorrow’s Technology and You 8/e Chapter 7

The Electronic File Cabinet: Database Basics

What Good Is a Database?

A database: A collection of information

Database software: Application software

(like word processing andspreadsheet software)

e.g. Microsoft AccessDesigned to create, update, query databases of information

(collections of information)

© 2008 Prentice-Hall, Inc. Slide 6

Tomorrow’s Technology and You 8/e Chapter 7

The Electronic File Cabinet: Database BasicsAdvantages offered by computerized databases:

Make it easier to store large quantities of information Make it easier to retrieve information quickly and flexibly Make it easy to organize and reorganize information Make it easy to print and distribute information in a variety of ways

© 2008 Prentice-Hall, Inc. Slide 7

Tomorrow’s Technology and You 8/e Chapter 7

The Electronic File Cabinet: Database Basics

Database Anatomy

Database program: a software tool for organizing the storage and retrieval of information

Database: a collection of information stored in an organized form in a computerTypically composed of one or more tables

A collection of related informationA collection of records

© 2008 Prentice-Hall, Inc. Slide 8

Tomorrow’s Technology and You 8/e Chapter 7

The Electronic File Cabinet: Database Basics

A record is the information relating to one person, product, or event.

Each specific (individual) piece of information in a record is called a field. (e.g. First name, last name, etc)

FieldRecord

Table

© 2008 Prentice-Hall, Inc. Slide 9

Tomorrow’s Technology and You 8/e Chapter 7

The Electronic File Cabinet: Database Basics

Database programs provide you with more than one way to view data:Form views

Show one record at a timeList views

Display several records in lists similar to the way a spreadsheet displays data

© 2008 Prentice-Hall, Inc. Slide 10

Tomorrow’s Technology and You 8/e Chapter 7

The Electronic File Cabinet: Database BasicsIn any view, fields can be

rearranged without changing the underlying data.

List View

Form View

© 2008 Prentice-Hall, Inc. Slide 11

Tomorrow’s Technology and You 8/e Chapter 7

The Electronic File Cabinet: Database Basics

Database OperationsUpdate: enter information into the database

e.g. a new customer)Browse: navigate through informationQuery: find records that match specific criteria

E.g. A pharmaceutical company marketing a new menopausal drug might query their database to find all female customers from the state of Illinois over 35 for a targeted ad campaign

© 2008 Prentice-Hall, Inc. Slide 12

Tomorrow’s Technology and You 8/e Chapter 7

The Electronic File Cabinet: Database BasicsSort: rearrange records (alphabetically or numerically)Print reports, labels, and form letters: A report is an

ordered list of selected records and fields in an easy-to-read format. Current database software has excellent report-generating

capabilities

© 2008 Prentice-Hall, Inc. Slide 13

Tomorrow’s Technology and You 8/e Chapter 7

The Electronic File Cabinet: Database Basics

Asking questions of the database is called querying. Generating a query is probably the most important and widely used feature of the database. Find all users over 25 years oldFind all products that have sold over 20,000 itemsFind all male users between 20 and 50 years old who live in

the state of Illinois whose license plate number begins with ‘TMX’

Find all products that have sold less than 1000 items. Remove those items from the catalog. Remove those items from the ‘Orders’ table.

© 2008 Prentice-Hall, Inc. Slide 14

Tomorrow’s Technology and You 8/e Chapter 7

The Electronic File Cabinet: Database Basics

Because queries are so important, most modern database management programs support a standard language for programming complex queries called SQL (Structured Query Language). SQL is usable on the large majority of database management systems. E.g. The following SQL query will query a table called ‘nobel’ to

name all the Nobel prize winners from the year 1950: SELECT winner_name FROM nobel WHERE year=1950

.

© 2008 Prentice-Hall, Inc. Slide 15

Tomorrow’s Technology and You 8/e Chapter 7

The Electronic File Cabinet: Database Basics

The Web: the world’s largest – but least organized –

database

© 2008 Prentice-Hall, Inc. Slide 16

Tomorrow’s Technology and You 8/e Chapter 7

The Electronic File Cabinet: Database Basics

Screen Test: Querying a Web Search Database

To search for articles online about a new method for recycling laser printer toner cartridges, you can visit a search engine, such as Google.

© 2008 Prentice-Hall, Inc. Slide 17

Tomorrow’s Technology and You 8/e Chapter 7

The Electronic File Cabinet: Database Basics

When you hit the “Search” button, the search engine will return a list of links, sorted by relevancy.

© 2008 Prentice-Hall, Inc. Slide 18

Tomorrow’s Technology and You 8/e Chapter 7

The Web as database

Because the data on the web is not stored in a relational database or DBMS (i.e. no underlying structured organization such as tables and forms), it cannot be queried in any structured way such as by using SQL.

Instead, web search engines search through all(!) of the pages on the web and using various algorithms, attempt to somehow organize the type of information stored on each page. It stores this information in something called an index.

When you type a query, the search engine, it searches its index to see which web pages best match your search text.

© 2008 Prentice-Hall, Inc. Slide 19

Tomorrow’s Technology and You 8/e Chapter 7

The Electronic File Cabinet: Database BasicsPersonal information manager (PIM): an

electronic organizerAutomates some or all of the following functions:

Address/phone book Appointment calendarTo-do listMiscellaneous notes

Handheld computers can share information with applications such as iCalendar running on PCs and Macintoshes.

© 2008 Prentice-Hall, Inc. Slide 20

Tomorrow’s Technology and You 8/e Chapter 7

The Electronic File Cabinet: Database Basics

© 2008 Prentice-Hall, Inc. Slide 21

Tomorrow’s Technology and You 8/e Chapter 7

Beyond the Basics: Database Management Systems

Database Management Systems Database management system (DBMS): manipulates data in a

large collection of files, cross-referencing between files as needed

© 2008 Prentice-Hall, Inc. Slide 22

Tomorrow’s Technology and You 8/e Chapter 7

Beyond the Basics: Database Management Systems

A DBMS can be used interactively, or can be controlled directly by other programs.

© 2008 Prentice-Hall, Inc. Slide 23

Tomorrow’s Technology and You 8/e Chapter 7

Beyond the Basics: Database Management Systems

What Makes a Database Relational?To most users, a relational database program is one

that allows tables to be related to each other.Changes in one table are reflected in other tables

automatically.To computer scientists, the term relational database

has a technical definition related to: The underlying structure of the dataThe rules specifying how that data can be manipulated

© 2008 Prentice-Hall, Inc. Slide 24

Tomorrow’s Technology and You 8/e Chapter 7

Beyond the Basics: Database Management Systems

The structure of a relational database is based on the relational model―a mathematical model that combines data in tables.

A database is relational when files are related to each other, such as this Student ID field in the Student file.

© 2008 Prentice-Hall, Inc. Slide 25

Tomorrow’s Technology and You 8/e Chapter 7

Beyond the Basics: Database Management Systems

The Many Faces of Databases

Large databases can contain hundreds of interrelated tables. A database management system can shield users from the

complex inner workings of the system, providing them with only the information and commands they need to get their jobs done.

© 2008 Prentice-Hall, Inc. Slide 26

Tomorrow’s Technology and You 8/e Chapter 7

Beyond the Basics: Database Management Systems

The Many Faces of Databases

© 2008 Prentice-Hall, Inc. Slide 27

Beyond the Basics: Database Management Systems

Database TrendsBatch processing: users accumulate transactions and input

them into the computer in large batches E.g. At end of the day, enter all the new customer records into the

databaseReal-Time computing: allows instant access to information Interactive processing: has replaced batch processing for

most applications Users can now interact with data through terminals, viewing and

changing values online in real-time. Batch processing is still used for jobs in which it makes sense to do a

lot of transactions at once. E.g. At end of the week, query ‘Payroll’ table for current employees and print out

paychecks

© 2008 Prentice-Hall, Inc. Slide 28

Tomorrow’s Technology and You 8/e Chapter 7

Beyond the Basics: Database Management Systems

Client/server computing involves two-way communications between applications running on the “client” PC and the “server” PC.

A travel agent might query an airline’s computer for schedule and fare information

© 2008 Prentice-Hall, Inc. Slide 29

Tomorrow’s Technology and You 8/e Chapter 7

Beyond the Basics: Database Management Systems

Downsizing and DecentralizingUsing a client/server approach

Today many businesses use a client/server approach, using database servers. Users can take advantage of the PC’s simple user interface and convenience,

while still having access to data stored on large server systems.

© 2008 Prentice-Hall, Inc. Slide 30

Tomorrow’s Technology and You 8/e Chapter 7

Using the web to query a database

Every time you search Amazon or any other online store, a query is being generated in a database maintained by that company.

Hypothetical examples: E.g. Select * from ‘books’ where keywords include Harry Potter Chamber E.g. Select schedule, fare from flights where departure city = ORD and

arrival city = YUL and departure date = Febuary 27

© 2008 Prentice-Hall, Inc. Slide 31

Tomorrow’s Technology and You 8/e Chapter 7

Beyond the Basics: Database Management Systems

Data Mining: The discovery and extraction of hidden predictive information from large

databases Uses statistical methods and artificial intelligence technology

Locates trends and patterns in data that would have been overlooked by normal database queries

“The goal is information

at your fingertips.”

Bill Gates

© 2008 Prentice-Hall, Inc. Slide 32

Tomorrow’s Technology and You 8/e Chapter 7

Beyond the Basics: Database Management Systems

Rules of Thumb: Dealing with Databases Choose the right tool for the job. Think about how you’ll get the information out before you put it in. Start with a plan, and be prepared to change your plan. Make your data consistent; inconsistencies can mess up sorting and

make searching difficult. Databases are only as good as their data. Query with care. If at first you don’t succeed, try another approach.