Databases and the InternetDatabases and the Internet

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

Router

Web Browser

Web BrowserHTTPTCP/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

TCP/IPWeb

ScriptPage

Web-to-DatabaseMiddleware

DB

HTMLPage

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 server-side

Client-Side Extensions

TCP/IPWeb

ScriptPage

Web-to-DatabaseMiddleware

DB

HTMLPage

Client-SideExtensions

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)