Hi, I read wrox book asp.net 1.1 in that author says
in fig 13.1

a html->application logic->database

is three tier architecture. how it can be a 3-tier

for this we need presentation layer()html->application logic->data-logic -> DATABASE

plz clarify

Raj

Three tier contains a presentation layer that is true which is html second it consits of business layer which is application logic and thrid the database which is data base which goes as above
html->application logic->database

Janamanchi Shrikanth Narsinha Ramulu

Conceptually, either of the scenarios could be considered "3-tier" - from a logical perspective data-logic/database could easily be considered the "same tier". This is a fine point that shouldn't be of concern.

In a dynamiclly generated web app (also sometimes called a data-driven site) it is often discussed as having another conceptual "tier":
Browser -> Web Presentation -> Business/Application Logic -> Data store.

Browser: contains some logic for validations and accepts user input
Web Presentation: Dynamically generates the HTML, and handles user requests
Business Logic: Does the work of the application.
Data store: Persists and retrieves data as required by the business logic.

I suggest that this isn't an area where it matters much exactly how you call things - the basic idea is that the logic is divided into various tiers that are best suited to handling the logic needed.


Woody Z http://www.learntoprogramnow.com