CIS515_Assignment4_KevinNock.docx - Assignment 4 Database...

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Assignment 4: Database Modeling and Normalization 1 Assignment 4: Database Modeling and Normalization Kevin A. Nock CIS/515 1/29/2017 Dr. Osama Morad
Assignment 4: Database Modeling and Normalization 2 Database Modeling and Normalization The Entity Relationship Model (ERD) is the model to represent the relationships among the entities. It has many components: Entity: That is the person, location, or anything by it can store the data. Attribute: It is the characteristic of the entity. Relationship: It is the association among the entities. Cardinality: It is the Constraint in the ERM, among the entities. The development steps of the ERM are the following: 1. Identify the Entities: We suppose that we have in this Government agency that is the Hiring Agency, and this has in its database the entities: Management, Employee, Department, and Customer. Then we can implement these entities by the ERM as the following: Entity by the Rectangle figure. 2. Determine the relationships: There are many relationships among the entities: MANAGEMENT manages EMPLOYEE. MANAGEMENT responsible of DEPARTMENT. MANAGEMENT hires CUSTOMER. EMPLOYEE works by MANAGEMENT. EMPLOYEE part of DEPARTMENT. EMPLOYEE manipulates with CUSTOMER. After determining the relationships, it must draw them with all the lines between the entities and the relationships, by the ERM: (Relationship by the Diamond figure). 3. Determine the relationship type (1:1), (1: M), or (M: N). Every relationship type has a specific symbol to implement it . For example One manager manages many employees: (1: M): We can implement this relationship as the following: One and only one manager can manage one or many employees.
Assignment 4: Database Modeling and Normalization 3 4. The end figure is the following:

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