DAL / BLL / PL 패턴, 구조란?

DAL / BLL / PL 패턴, 구조란?

요즘은 MVC 패턴으로 불리고 있지만 이전에는 대기업에서 DAL BLL PL 패턴이라하여 MVC 패턴과 유사하게 사용하던 패턴이

있었다고 한다

주요 내용은 아래와 같고, MVC 패턴과 상당히 유사하다

DAL(Data Access Layer)

provide an abstraction of the underlying data source(s) (Where and how the information coming from/going to business layer is stored)

Methods that access the underlying database

data tier (database, data storage): a database, typically a RDBMS such as MySQL or Oracle

directly manipulate the database by the data, delete, change, check

sometimes also referred to as the persistence layer, its main function is responsible for access to the database, you can 

access the database system, binary files, text documents or XML document

 

BLL(Business Logic Layer)

everything that is related to the logic of the application (How is the information coming from presentation layer treated)

all constraints about the data (unique name, name without symbols, valid date, etc), methods for manipulating business 

objects (create new user, add new order, etc)

logic tier (application/business logic): business logic, typically in an application server (based on J2EE, ASP.NET or whatever)

issue-specific operations, but also can be said that the operation of the data layer, business logic processing data

PL(Presentation Layer) = UI

put everything that is related to user interface. (What the user sees)

all the graphical things, fields where user inserts data, menus, pictures, etc

presentation tier (actual user interface): browser, or fat client

The popular talk is to show to the user interface, the user when using a system he WYSIWYG

Located in the outermost layer (top-level), closest to the user

For displaying data and receiving user input data, to provide users with an interactive operation of the interface

WYSIWYG

위지위그(WYSIWYG: What You See Is What You Get, "보는 대로 얻는다")는 문서 편집 과정에서 화면에 포맷된 낱말, 문장이 

출력물과 동일하게 나오는 방식을 말한다.

참조: http://www.databasesql.info/article/40068680/