TUGAS E-R DIAGRAM

TUGAS 2 : Konsep dan Arsitektur Sistem Basis Data

·          Summary

A data model is a plan for building a database. To be effective, it must be simple enough

to communicate to the end user the data structure required by the database yet detailed

enough for the database design to use to create the physical structure.

The Entity-Relation Model (ER) is the most common method used to build data models

for relational databases. The next section provides a brief introduction to the concepts

used by the ER Model.

·           The Entity-Relationship Model

The Entity-Relationship (ER) model was originally proposed by Peter in 1976 [Chen76]

as a way to unify the network and relational database views. Simply stated the ER model

is a conceptual data model that views the real world as entities and relationships. A basic

component of the model is the Entity-Relationship diagram which is used to visually

represents data objects. Since Chen wrote his paper the model has been extended and

today it is commonly used for database design For the database designer, the utility of the

ER model is:

* it maps well to the relational model. The constructs used in the ER model can

   easily be transformed into relational tables.

* it is simple and easy to understand with a minimum of training. Therefore, the

   model can be used by the database designer to communicate the design to the end

   user.

* In addition, the model can be used as a design plan by the database developer to

implement a data model in a specific database management software.