The advantage of three tier Architecture is code reusability. In starting live practice for three tier Architecture, there are three layers,
- BAL
- DAL
- UI (PAL)
BAL (Business Access Layer)
This layer defines a function or class to use to transfer data into Data Access Layer and Presentation Access Layer.
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DAL(Data Access Layer)
This layer provides contents of logic to implement a program, for example, a program to add, insert, or update; then all logic of this code is DAL Layer.
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UI (PAL) User Interface Presentation Access Layer
The design purpose to use this Layeris simple -- to view all design layout from your program's webpage code.
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