INTERNET DATABASE

1
Chapter 9

• INTERNET DATABASE

2
Chapter 29 - Objectives

• Basics of Internet, Web, HTTP, HTML, URLs.
• Advantages and disadvantages of Web as a database
  platform.
• Approaches for integrating databases into Web
• Scripting Languages
• Common Gateway Interface (CGI)
• HTTP Cookies

3
Internet and E-commerce

• Internet a worldwide collection of
  interconnected computer network
• E-commerce customers can place and pay for
  orders via the businesss web site (Amazon.com)
• Benefits of e-commerce
• Worldwide market buy from anywhere
• Productivity no wastage of time
• Cost reduction less time energy
• Improved customer services ease the customer
  (faqs, knowledge on products, other services)

4
Internet Services

• E-mail to send mail and file attachment
• Worldwide web to browse for information stored
  anywhere and do business transaction
• File transfer to download and upload file
• News to join a news group
• Chat room to join a discussion or chat room

5
Worldwide web

• Internet computers connected using a standard
  protocol TCP/IP
• Worldwide web resources stored on the web
• Web browser software to browse the web (IE..)
• Web server software to responds to clients
  request
• Web page text written in HTML, static and
  dynamic

6
Worldwide web (cont.)

• Hyperlink linking the web page
• Hypertext refer to different types of documents
  (text, graphics, imagesin the hyperlink)
• Web site refer to server and collection of the
  web pages
• http (hypertext transfer protocol) protocol
  used by client and server to communicate

7
Client Functions

• Can be extended
• Plug-ins browser can activate automatically
  when required external application (exp if
  file ext. is .pdf then launches Adobe Acrobat
  Reader)
• Active-X Microsofts specification for writing
  programs that will run inside its browser.
• - It extends the browsers ability by providing
  controls such as calendar and calculator.
• - These controls allows to manipulate data
  within the browser. Controls usually written in
  VB or Visual C

8
Client Functions

• VBScript Microsoft product based on Visual
  Basic
• - HTML page containing embedded code
  written in VBScript
• - can be executed by web browser
• JavaScript Netscape product (Netscape
  Communicator)
• Java Product of Sun.
• It runs on top of a web browser/applets.
• Java routines are compiled and stored in server.
  
• HTML contain calls to the routines.
• Browser downloads the routines from the server
  and executes it.

9
Server Functions

• Query processing from browser (client) to server
• Browser send a web page request to the server
• Server receive the page request and validate.
  Then, pass to the middleware
• Middleware read the script, validate and execute
  it. Send SQL command to the DBMS, retrieves the
  info. And send the result back to the middleware
• Server takes and send the page to the browser

10
Web server interface

• Web server provide standard interface to
  communicate with external program
• Two common interfaces
• Application Programming Interface (API) (has
  dynamic link libraries, DLL), disadvantage is it
  is vendor and OS specific
• Common Gateway Interface (CGI)

11
Internet / Intranet and its Security

• Internet - a worldwide collection of
  interconnected computer network
• Intranet an internal corporate network, LAN or
  WAN
• Benefits of intranet
• Ease of use
• Open standard
• Platform independence Runs anywhere
• Multiple data source
• Uniform interface
• Shorter development time

12
Internet / Intranet and its Security

• Firewall a software / hardware components that
  limits and control
• Data traffic to an organizations database from
  the outside world
• Data that are permitted to flow from an
  organization the outside world.

13

• END