Transcript Chapter 24 - Personal Web Pages

ITIS 1210
Introduction to Web-Based
Information Systems
Chapter 24
How Websites Work with Databases
Databases
 Enables Web sites to search for
information
 Not part of the “visible” Web!
 Web site becomes “front end” for a
database application
 Usually involves entering search terms
and viewing results
Databases
 Example: www.yahoo.com
 Yahoo’s Web page includes
 Search dialog box
 Enter keyword
 Search button
 Enable search
 What is returned is an HTML-formatted page
with data from Yahoo’s database relevant to
the keyword
Databases
 Interaction can be two-way
 Users asked to “register”
 Provide identifying information
 Site stores this in their database
 For future reference
 For data collection
Databases
 Database can be simple or complex
 Excel spreadsheet
 Access database
 Oracle SQL database
 CGI – Common Gateway Interface
 Bridges Web site (using HTML) and
 Database (using Excel, Access, SQL, etc.)
 PERL & .NET also provide bridges
How the Web Works with Databases
http://search.yahoo.com/cgi-bin/search?p=public+relations&ln=En
How the Web Works with Databases
 Server
 Folder where CGI executables are stored
 “bin” is short for “binary” meaning a program
that can be executed
 Name of CGI script to be run
 Parameters to control what script does
 Space (+)
 Delimiter between different terms of string
How the Web Works with Databases
 User enters search term in form on
browser
 Initiates search
 Presses WEB SEARCH
 Presses ENTER
 Client formats a query string and sends it
to Web server
 The “search?” part calls a CGI script
How the Web Works with Databases
 The rest are parameters that control what
happens
 Might see /cgi-bin to indicate directory
where executable can be found
 Delimiters
 & separates search terms and other
parameters
 + takes place of space
 Query string arrives at the Web server
How the Web Works with Databases
 CGI processes is
 Sends query to database
 Database processes query and returns
results to CGI
 CGI returns results to the Web server
 Web server creates a new HTML page
and sends it back to the client
 Client displays results