PPT-Entity Relationship Diagram (ERD)

Entity Relationship Diagram ERD ERD adalah model data yang menggunakan beberapa notasi untuk menggambarkan data dalam konteks entitas dan hubungan yang . Joe Meehean. 1. Entity Relationship Model. Entity type. an object (noun). e.g., student. attributes (e.g., last name). Relationship. association between entity types. bidirectional relationship between entities. 1. Enhanced-ER (EER) Model Concepts. Includes all modeling concepts of basic ER . Additional concepts: subclasses/. superclasses. , specialization/generalization, categories, attribute inheritance. Entity. “An . entity. is a business object that represents a group, or category of data.”. 1. Do we know a similar concept? . 1) Stephens, R.K. and Plew. R.R., 2001. . Database Design. . SAMS, Indianapolis , IN.. 2. Outline. Data Modeling: Big picture. E-R Model. Attributes. types. Relationships. connectivity, cardinality. strength, participation, degree. Entities. composite entity. supertype/subtype. Table Normalization. Practice . (3) . :. Data Modelling & the Entity-Relationship Approach. UFCE8V-20-3 . Information Systems Development 3 (SHAPE HK). E-R modelling concepts (1). Entity & Attribute. An . entity. Chen Model. Entity. represented by a rectangle with its . name in capital . letters. .. Relationships. represented by an active or passive . verb inside the diamond . that connects the related entities. Chapter 2. Overview of Database Design. Conceptual design. : . (. ER Model . is used at this stage.) . What are the . entities. and . relationships. in the enterprise. ?. Students . sign up. . for . The process of database design is an iterative rather than a linear or sequential process. . The . verb . iterate . means “. to do . again or repeatedly.” . An . iterative process . is, thus, one based on repetition of processes and procedures. . Modeling:. 1. CIS . 4365 . Entity Relationship Diagrams. Part 2. Your Individual Project. 2. CIS 4365 . Entity . Relationship Diagrams. We will develop the ERD as a class; you must execute complete the project . Data Modeling What are you keeping track of? You begin to develop a database by deciding what you are going to keep track of. Each “thing” that you are want to keep track becomes an entity in your database. Chapter Five: Data Modeling with the Entity-Relationship Model Chapter Objectives To understand the two-phase data modeling/database design process To understand the purpose of the data modeling process 2. Organization. :ER Case Study. Organization made up of various departments, each having a name, identifying no., and an employee who is the manager. A department may be located in different places. Information about employee includes name, identification number, birth date, address, sex, and salary. Each employee is assigned to one department. The date the manager is appointed to a department is also tracked. Employees may be directly supervised by another employee. Each project within the organization is controlled by a department. Employees (not necessarily from the controlling dept.) are assigned to projects. Information about projects includes project name, no., and location. Hours spent by employees on each project are also kept.. Queries . Using . an . Extended . Graph Model. Ankur. . Agrawal. . S. Sudarshan . Ajitav. . Sahoo. . Adil. . Sandalwala. . Prashant. . Jaiswal. . IIT . Bombay. History of Keyword Queries. These models can be used both by the analysis and design processes. They are somewhat abstract and hence not biased towards implementation. They are somewhat concrete because they add a little more details than requirements.