Pemrograman Sistem Basis Data Chapter III Data Model

In This Chapter You Will Learn Pentingnya Model Data Abstraction Data Model Perkembangan Model Data

Pentingnya Data Model ??? Follows Business Rules Communication Tools (Designer, Programmer, End user) End-users have different views and needs for data

Contoh Business Rules PT A menetapkan sistem pembayaran dilakukan dengan tunai dan kredit. Jika kita tidak pandai menganalisa maka mungkin saja dapat terjadi redudancy data yang menyebabkan terjadinya anomali data. Dirjend Pu mempunyai aplikasi keuangan dengan mengikuti Bagan Standar Akun yang ditetapkan MenKeu. Tiba2 ganti mentri dan BAS berganti mengikuti aturan yang baru sehingga terjadi Perubahan sistem secara menyeluruh.

Important Business Rules Membantu terciptanya Data Model yang akurat sesuai dengan kebutuhan perusahaan. Membantu desaigner mengerti kebiasaan, aturan, dan lingkup data. Membantu desaigner untuk mengerti proses bisnis dari perusahaan tersebut.

Abstraction Data Model A data model instance may be one of three kinds according to ANSI in 1970: Conceptual Model Internal Model Eksternal Model

Conceptual Model Merupakan sebuah Map dari konsep dan hubungannya secara lebih rinci menjelaskan tentang entity class dan hubungan antar entity class tersebut bukan desain database. Contoh : Person mungkin dapat memiliki satu order atau lebih. Tetapi order hanya dapat dimiliki satu order.

Conceptual Schema(lanjt)

Evolusi Model Data Hierarchical Network Relational Object Oriented

Hierarchical Data Model A hierarchical data model is a data model in which the data is organized into a tree-like structure. The structure allows repeating information using parent/child relationships: each parent can have many children but each child only has one parent (also known as a 1:many ratio ).

Examples of Hierarchical Data Represented as Relational Tables In this model, the employee data table represents the "parent" part of the hierarchy, while the computer table represents the "child" part of the hierarchy. As shown, each employee may possess several pieces of computer equipment, but each individual piece of computer equipment may have only one employee owner.

Hierarchical Data Model

network model Where the hierarchical database model structures data as a tree of records, with each record having one parent record and many children, the network model allows each record to have multiple parent and child records, forming a generalized graph structure.

network model

Relational Model

Object Oriented Data Model

Object Oriented Data Model Modeled both data and their relationships in a single structure known as an object Basis of object oriented data model (OODM) OODM becomes the basis for the object oriented database management system (OODBMS)