Databases and
and the
the Internet
Internet
Databases
Lecture Objectives
•
•
•
•
•
Databases and the Internet
Characteristics and Benefits of Internet
Server-Side vs. Client-Side
Special Considerations
Overview of Database Internet
Technologies
Databases and the Internet
• Where do you see databases on the net?
– E-Commerce
– Educational (Database of Journals, …)
– Medical Sites (Database of Images, …)
• But what is the advantage of having a
database on the internet?
– Increase in Volume of People Viewing
– Make your data public!
Database and the Internet
• Does Database Design change?
– NO!
– “The effects of bad database design,
implementation and management are
multiplied in an environment in which
transactions may be measured in millions per
day, rather than hundreds per day”
Characteristics and
Benefits of the Internet
• Hardware and Software Independence
– No need for multiple platform development
– Runs on Existing Equipment
• (for the most part – advancing technologies)
• Simple User Interface
• Location Independence
• Rapid Development at Low Costs
Database and the Internet
Web Browser
Router
Web Browser
HTTP
TCP/IP
Basic Terminology
• Internet
– A worldwide network of networks
– Uses Standard Network Protocol TCP/IP and devices
known as Routers
• TCP/IP
– Transmission Control Protocol/Internet Protocol
– Determines the rules used to create and route
packets of data between computers in same or
different networks
– Unique identifier / made up of network and host
Basic Terminology Cont.
• Router
– Special Hardware/Software combination
– Connects multiple and diverse networks
– Delivers the packets of information from local to
remote network
• World Wide Web
– Worldwide network connection of web pages
• Web Pages
– A document created in Hypertext Markup Language
Basic Terminology Cont.
• Hypertext Transfer Protocol (HTTP)
– Standard Protocol used by Web Browser and
Web Server to communicate
– Uses TCP/IP
• Web Server
– Specialized Hardware/Software whose only
function is to “listen” for client requests,
process them, and send a web page back
– Uses HTTP
Server-Side Extensions
• Web server and Web browser can only
interact via HTML Pages
• Must extend Web Server capabilities to
include database queries
– Server-Side Extensions
• Program that interacts directly with the web server
to handle specific types of requests
• I.e.. Retrieving data from a database
– Web-to-database Middleware
Server-Side Extensions
Script
Page
TCP/IP
Web
HTML
Page
Web-to-Database
Middleware
DB
Client-Side Extensions
• Adds functionality to the web browser
– Java and JavaScript
– Active X and VB Script
– ASP, ASP .NET
• Allows for input validation on forms,
caching of web pages
• Less work needs to be done on the serverside
Client-Side Extensions
Client-Side
Extensions
Script
Page
TCP/IP
Web
HTML
Page
Web-to-Database
Middleware
DB
Special Considerations
• Sound Database Design and Implementation
– Volume of Use Increases
• Database Security
– Holding Credit-Card Information (for example)
– Firewalls, encryption, …
• Data Integrity
– Majority of Information will entered via web page interface
(client-side extensions necessary)
• Data Types
– Browser dependence and Web-To-Database middleware
dependence
Internet Database Technologies
• Common Databases for the Web
– Microsoft SQL Server
• Used Primarily for Microsoft Technologies
– Internet Explorer, .NET, …
– MYSQL
• Freeware/Open Source Database
– (anybody can run it from their house!)
• Used Primarily with PHP, mostly Unix based
• Differences?? (Too much for us to handle)