Transcript Chapters 14 & 15

Chapters 14 & 15
Internet Databases
E-Commerce
 Bringing new products, services, or ideas to
market, supporting and enhancing business
operations
 Mainly identified with the use of the Internet
as a medium to transact business and add
value to an organization.
 Changed Business Environment
Benefits of E-Commerce
 Convenience
 Quick and Convenient Comparison
Shopping
 Reduced Cost / Increased Competition
 24 / 7 / 365 operations
 Global Access
 Lower Entry Barriers
 Increased Customer Market Knowledge
Disadvantages of E-Commerce
 Hidden Costs
– Hardware
– Software






Technology is not perfect
Thin profit margins (must be competitive)
Security
Loss of Privacy
Low Levels of Customer Service
Legal Issues
Major E-Commerce Styles
 Business to Business (B2B)
 Business to Consumer (B2C)
– Consumer to Business
– Consumer to Consumer
– Government to Consumer
– Government to Business
 IntraBusiness (using Intranet)
E-Commerce Architecture
 3 Layered Organization of Services that
interact, using a common set of protocols.
The Internet is the main transport medium.
 Basic Internet Services
 Business Enabling Services
 E-Commerce Business Services
Basic Internet Services







Web Browser
HTML
FTP
HTTP
TCP/IP
Web Server
E-Mail
Business Enabling Services









Security
Personalization
Database Integration
Usability Testing
Web Site Monitoring and Analysis
Transaction Processing
Search
Messaging
Wireless Device Support
E-Commerce Business Services







Inventory
Ordering
Tracking
Product Support
Customer Service
Shipping
Etc.
Security
 Protect transaction data from unauthorized modifications during
Internet travel – Transaction Security
– Secure Socket Layer
– S-HTTP
 Authentication - Warrantee identity of transaction participants (Buyers
and Sellers)




Protect Resources (data and computer)
Customer’s personal data
Privacy Issues
Property against Criminal Activity
– Digital Certificated
– Encryption
 Private Key
 Public Key
 Resource Security
– Protect against virus, hackers, DOS attacks
Database Design for E-Commerce
 Don’t reinvent the wheel
 No need for ‘new’ design techniques
 Scope
– Facilitate sales of products and services
– Show products and services
– Conduct basic sales transactions
– Customer Service
– Product Returns Web Customer Profiling
Basic Business Rules
 Sell Products  Product and Customer
Tables
 Customer may place multiple orders
– 1:M Relationship
 Order contains Multiple Lines
– 1:M Relationship
 Order Lines refer to one Product
– 1:M Relationship
XML – Extensible Markup Language
 Meta-Language
 Represents and Manipulates data elements
 Facilitates Exchange of structured documents over
the web
– World Wide Web Consortium (W3C) published standard
definition in 1998
 Allow definition of meta-tags to describe data
elements
 Case Sensitive
 Not A Replacement for HTML
XML – Document Type Definition
 Files with .dtd extension to describe XML
elements
 Provides composition of database’s logical
model
 Defines syntax rules for each XML
documents
 Defines Valid tags
XML Schema
 Advances data definition language used to
describe structure of XML documents
 Closely maps database terminology and
features
 Checks for database types
 Validates data for out-of-range values
 XML Schema Definition (XSD) files use
syntax like SML document
Web Databases
 Stateless Environment – The web is a
stateless system.
 Data processing requires additional software
– Java
– Java Script
– VB Script
Web Database Connectivity
 Allows rapid response to competitive
pressures
– New Services
– New Products
 Enhanced Customer Support
 Fast Effective Information Dissemination
Characteristics / Benefits of Internet
Technology
 Hardware / Software Independence
– Cost Savings
– Uses Existing Equipment
– Platform Independency
 Common Simple User Interface
– Reduced Training and Support
 Location Independence
– Global Access
– Reduced Costs for Dedicated Connections
 Rapid Development at Manageable Cost
– Development Tools (Plug and Play)
– Low Entry Costs (Often Free Web Servers)
– Available Software and Access Tools
Web Server Interfaces
 CGI – Common Gateway Interfaces
– Uses Script files to connect to database
– Perl, C++, VB
 API – Application Programming Interface
–
–
–
–
Newer
More Efficient
Uses DLL’s
Memory Resident
 Netscape API
 Internet Server API (Microsoft)
 Cold Fusion – Web Application Server
Web Server Application
 Middleware application
 Expands functionality of Web servers by
connecting them to wide range of services
– Databases
– Directory Systems
– Search Engines
 Provides a Consistent Run-Time Environment for
Web-Applications
 Allows Client to Interact with Databases and
Present Database-Driven Data in a Web Page
Server Side Extension
 Part of Web Server Application
 Interacts directly with web server
 Handles specific requests
Middleware Connectivity to
Databases
 Native SQL
 ODBC (most common)
 OLC DB – Object Linking and Embedding
Database Interface
– Windows
Web Browser – Client Machine
 End User Web Interface
 Interprets HTML
 Client-Side Extensions
– Plug Ins
– Java / Java Script
– Active X and VB Script
Special Considerations for Internet
Databases
 Involved more than just database-enabled
applications
 Data Types
– Integrate from Multiple Sources
– How to store and extract data
– Overhead
– Browser Support
Special Considerations for Internet
Databases
 Data Security
–
–
–
–
Web Server Level
RMDBS Vendor
Web to Database Middleware
Must Support E-Commerce
 Transaction Management (stateless env.)
 Client Side Data Validation
 Cannot Use Multiple Table Data Entry – Requires
Denormalization of Tables
 Other Operational and Management Challenges