View Single Post
  #2 (permalink)  
Old February 3rd, 2011, 09:40 AM
melvik melvik is offline
Friend of Wrox
Points: 3,558, Level: 25
Points: 3,558, Level: 25 Points: 3,558, Level: 25 Points: 3,558, Level: 25
Activity: 0%
Activity: 0% Activity: 0% Activity: 0%
 
Join Date: Jun 2003
Location: California, USA
Posts: 996
Thanks: 2
Thanked 11 Times in 11 Posts
Send a message via Yahoo to melvik
Default

well, usually in advance software design we use laying to apart software tasks where application works independently in layers. It's contains of min 2-N layers (Microsoft has 4)
but usually 3 as u mentioned.
1. UI = User Interface
2. BL = Business Layer or Logic
3. DA = Data Access

let me explain u in an instance:
u have a ASP.NET page where users register.
u have some rules like checking if user is able to register according to her/his birthday & ...
1.ur ASPX file is ur UI where ppl see.
2. u use some classes & functions to check the rules (age story) its a separate project or at least another file
3. u have a different project who is the only responsible for ur Data part.

its like this:
1- user see the page & enter some data & PUSH REGISTER BUTTON
2- ur page sends user entered data to BL & it checks some rule like age, & if it was ok, calls the DL methods to add data to DB, or if its not ok, doesnt send & may gives a report back to user in UI ...
3- ur DA is only doing CRUD operations such as making connection & executing some T-SQL commands.

Its a long story u should go for, not too simple to reply u here, but not as hard as u cant...
HTH
__________________
Always,
Hovik Melkomian.
Reply With Quote