Use of Business Layer in 3-tier architecture

Question

I am implementing 3-tier architecture. I just wanted to know the role of business layer in 3-tier architecture.

I am developing application in using entity framework. So I have entity object which is accessiable in PL,BL & DL. My question is whether input assignment to entity object should be in PL OR BL.(Consider there is save method)

Answer 1

I think, you have read about layered architecture. You can refer to the details on Microsoft's site: http://msdn.microsoft.com/en-us/library/ff648105.aspx

As the name suggests, business layer contains all business logic implementations. The presentation layer just calls up services in the business layer or invokes assemblies (DLLs) of the business layer and passes on the input.

Let me know what kind of application you do have. That will enable me to provide some more contextual information.

Answer 2

Business layer is the class where we write the functions which get the data from the application layer and passes through the data access layer.