22-03-2012, 04:42 PM
Application Design and Development
8 appilicatinal design and developement.ppt (Size: 340 KB / Downloads: 24)
User Interfaces and Tools
Most database users do not use a query language like SQL.
Forms
Graphical user interfaces
Report generators
Data analysis tools (see Chapter 18)
Many interfaces are Web-based
Back-end (Web server) uses such technologies as
Java servlets
Java Server Pages (JSP)
Active Server Pages (ASP)
The World Wide Web
The Web is a distributed information system based on hypertext.
Most Web documents are hypertext documents formatted via the HyperText Markup Language (HTML)
HTML documents contain
text along with font specifications, and other formatting instructions
hypertext links to other documents, which can be associated with regions of the text.
forms, enabling users to enter data which can then be sent back to the Web server
Web Interfaces to Database (Cont.)
Dynamic generation of documents
Limitations of static HTML documents
Cannot customize fixed Web documents for individual users.
Problematic to update Web documents, especially if multiple Web documents replicate data.
Solution: Generate Web documents dynamically from data stored in a database.
Can tailor the display based on user information stored in the database.
E.g. tailored ads, tailored weather and local news, …
Displayed information is up-to-date, unlike the static Web pages
E.g. stock market information, ..
Uniform Resources Locators
In the Web, functionality of pointers is provided by Uniform Resource Locators (URLs).
URL example:
The first part indicates how the document is to be accessed
“http” indicates that the document is to be accessed using the Hyper Text Transfer Protocol.
The second part gives the unique name of a machine on the Internet.
The rest of the URL identifies the document within the machine.
The local identification can be:
The path name of a file on the machine, or
An identifier (path name) of a program, plus arguments to be passed to the program