Somthing about 3-Tier architecture

Three Layer:

1. DAL (Data Access Layer)
2. BLL (Business Logic Layer)
3. PL ( Presentation Layer)

· All code that is specific to the underlying data source – such as creating a connection to the database, issuing SELECT, INSERT, UPDATE, and DELETE commands, and so on – should be located in the DAL.

· Data Access Layers typically contain methods for accessing the underlying database data.

· The presentation layer should not contain any references to such data access code, but should instead make calls into the DAL for any and all data requests.

In n-tier models, which tier is best suited for implementing the view, and controller components of an MVC application?

A Client Tier B Web Tier C MVC Tier D Business Tier E EIS Integration Tier F EIS Tier