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Instructor Information Here
Copyright © 2003 Addison-Wesley
Internet Information Systems
• What are the major components of Web systems?
• How are Web pages created using HTML?
• What are Web servers and information servers combine
to create Web sites?
• How is a typical Web site organized?
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Components of the Web
•
Web browser
– Formats and displays Web pages
– Requests pages from Web server
– Collects user inputs and sends
them to server
•
Web server
– Sends Web pages to browser
– Accepts and processes user input
– Sends requests to information
server
•
Information Server
– Accepts requests from Web
server
– Manages complex information
resources
– Contains database server
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Sample Web Page
• A Web page is the formatted display of information
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Sample HTML Document
1 <html><head>
2 <!-- Home page for BigHit Online Demonstration Site-->
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<title>Welcome to BigHit Online</title>
4 </head>
5 <body bgcolor="#c2e1e7" link="black" vlink="black" alink="black">
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<font face="tahoma" "size=14px">
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<center>
8
<!--lines for heading with image omitted -->
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<table width="715" border=2 cellpadding="5">
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<!-- lines for first row omitted -->
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<tr> <!-- second row -->
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<td><h3>
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<a href=" http://www.web4data.com/bighit/index.html">
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BigHit Video Simple Sample Web pages and ASP scripts
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</a></h3></td>
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</tr>
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<!--lines for third row omitted -->
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</table>
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<!-- lines for footer omitted -->
20
</center>
21 </font>
22 </body>
23 </html>
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Web Server
•
A computer program that services browser requests
– A Web server is software that knows how to service requests
– A Web server computer is a computer that executes a Web server program
•
Browser request for a specific HTML document may be serviced from
the Web server computer’s disk
http://www.web4data.com/index.html
<html><head>... </html>
Web
Browser
Web
Server
www.web4data.com
<html><head>... </html>
Files
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/index.html
Generating HTML Documents
• An Information Server may be a computer that generates HTML
documents for storage in a Web server
– New York Times has regular updates of its pages from an information
server that contains all of its news stories and other information
– Someone requests the recreation of the home page (index.html)
index.html:
<html><head>...</html>
Web
Server
generate
index.html
www.nytimes.com
index.html:
<html><head>...</html>
Files
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Information
Server
A Sample Web site
• Consider the BigHit Online video sales Web site
• Each page will be generated in response to a customer request
– Browser creates request for page
– Web server determines what information is included in request and what
is required for response
– Web server updates database (information server) with supplied
information
– Web server asks database for information needed for response
– Web server creates HTML document with information
– Web server sends document to browser for format and display
• Look at these 3 types of pages
– Page to display customer information
– Page to select videos for purchase
– Page to display purchase reciept
• What information is needed for each page?
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Sample Database Tables
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Customer Information Page
• Information content of page is a single row of the Customer table
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Purchasing Web Page
•
•
•
•
Information content is some of the rows of the Movie table
Some components of the page are for user-supplied information
The number of copies of each video for purchase is sent to the Web
server
The number of copies is used to add new rows to the Sale table
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Receipt for Purchase
•
Information on this page comes from all three
tables
–
–
The customer information comes from the row
of the Customer table with accountId 101
Each row of the purchase details comes from a
combination
• One row of the Sale table for customer 101
for movieId, quantity, format, and cost
• One row of the Movie table with the same
movieId for title and price
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Sample SQL Statement
• SQL (Standard Query Language) is the language that is used to
communicate with database servers
• The information for the sales receipt entries is produced by sending
this SQL statement to the BigHit Online database server
– select Movie.movieId, Movie.title, Sale.format, Movie.dvdPrice,
Movie.tapePrice, Sale.quantity, Sale.cost
from Movie, Sale
where Movie.movieId = Sale.movieId and Sale.accountId = 101
and Sale.saleDate = 'Mar 5, 2002'
Copyright © 2003 Addison-Wesley