Transcript An Introduction to Database Access on the Web

An Overview of Database Access on
the Web
Using ASP and Microsoft Database Technology
Sheffield Hallam University 2003
Structure of Session
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Lecture: An Overview of Database Access Over the Web
(30 mins)
Reading exercise 1 (20 mins):
A. Introduction to Client Server technology on the web
B. Introduction to HTML, Scripting Languages ASP technology
C. An introduction to ASP
D. Getting acquainted with Microsoft Access databases
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Activity 1: Experimenting with HTML (20 mins)
Activity 2: Experimenting with ASP (25 mins)
Activity 3: Playing with the Shopping Cart e-commerce
Site (15 mins)
Structure of Presentation
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Introduce ASP and Microsoft Database
technologies
3 Tiered Network architecture
Example scenario
Simulate working example of ASP
Demonstrate Shopping Cart e-Commerce Site
Summarise Presentation
Discuss areas for further study
What is Microsoft Access?
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Microsoft’s economical, Small-Scale RDBMS
Currently release is Access 2002 (XP)
Little brother to Microsoft SQL Server
Front-end GUI building functions
Moderate performance, 100 max simultaneous
users, good enough for smaller e-commerce projects
Intuitive GUI, VBA programming, can build selfcontained database applications
Access 2002 – Integrated Development
Environment
SQL Server
SQL Server is very popular
 Similar functionality to Access
 Many more advanced features e.g. stored
procedures, triggers
 SQL suitable for larger scale e-commerce
i.e 1000’s simultaneous users
 Well worth being familiar with it!
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SQL Server 2000 - IDE
What is ASP?
ASP stands for Active Server Pages
 Developed by Microsoft
 Normally coded using VBScript
 Language used to ‘script’ operations on the server
– invisible to client machine
 Highly popular, used by 1000’s Web sites e.g.
Halifax.co.uk
 Enhances Web pages by adding dynamic content
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What can ASP do (that HTML can’t)?
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Interact with databases to read and write data
Read and write ‘cookies’ to a users computer
Track user activity within a Web site
Check user input (validation)
Talk to other applications on server e.g. Word
Talk to custom built applications on server
Send bulk email or automated email responses
Return dynamic HTML code back to the client
Read data from the end of a URL (called a query
string)
What is ASP used for on Web?
Search engines
 Online banking
 E-commerce
 Web mail
 Financial calculators
 Online mortgage, credit, loan applications
etc
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Sample of ASP code
<%
dim req, copyright
copyright =" This sample program Copyright SHU, 2003"
req=request.QueryString("action")
if req = "search" then
response.write(“Searching Database”)
call searchResponse()
end if
%>
Scenario – Phase Test Marks
Students take phase tests on a regular basis
 The tutor logs the marks for these tests on a
table called tblmarks, on an Database called
phase
 The course leader uses an ASP page to request
the mark of any student and a pass/ fail status
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Scenario – Phase Test Marks
Student
completes
Phase Test
Test
Marks
phase
database
Course Leader
Request requests mark
Database
Tutor records
marks
Test
Marks
Student
Data
Architecture
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Model of Client-Server Architecture
Web Server (e.g. Microsoft IIS)
Request
The
Internet
Client (e.g. Windows 2000)
Data
in
Data
Out
Keyed
Data
ASP
Pages
ASP
pages
Req.Data
Database
Data
ASP 1 - Phase Tests
ASP Code Walkthrough
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ASP code is contained within <% tags
VBscript syntax almost identical to VB
ASP code reads querystring from URL to
determine actions
ASP dynamically returns HTML via response.write
ASP seamlessly connects to SQL database
Uses server-side validation to check form data
Uses inline script e.g. <%=copyright%> to insert
data directly into HTML code
ASP 2 – Small E-commerce Site
ASP 3 – Pushing the limits of ASP
Summary of Lecture
Introduced ASP, HTML and Access
technology
 Reviewed client-server architecture
 Simulated how ASP can be used to retrieve
data from an SQL Server database
 Explained ASP code in detail
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Areas For Further Study
What are the pros and cons of using ASP?How do alternatives compare e.g. JSP
 How does the performance of ASP compare
to VB – why is there a difference?
 How much of an improvement is ASP.net?
 How much better is SQL Server 2000 than
Access?
 In which business situations would you
choose SQL Server over Access?
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