Enhanced E-R Model
•Download as PPT, PDF•
28 likes•292 views
Representing Supertypes and Subtypes Specifying Constraints in Supertype/ subtype Relationships Entity Clustering Union and Aggretion
Recommended
More Related Content
More from Dr. Rosemarie Sibbaluca-Guirre
More from Dr. Rosemarie Sibbaluca-Guirre (20)
Recently uploaded
Recently uploaded (20)
Enhanced E-R Model
- 1. IS-DBS 313 Presented By: Dr. Rosemarie S. Guirre Enhanced E-R Model
- 2. DATA MODELLING Presented By: Dr. Rosemarie S. Guirre | IS-DBS 313-2 Modeling the Rules of the Organization E-R Model Notation Modeling Entities and Attributes Modeling Relationship WRAP UP
- 3. TOPICS Presented By: Dr. Rosemarie S. Guirre | IS-DBS 313-2 Representing Supertypes and Subtypes Enhanced E-R Model Specifying Constraints in Supertype/ subtype Relationships Entity Clustering Union and Aggretion
- 4. WRAP UP Presented By: Dr. Rosemarie S. Guirre | IS-DBS 313-2 high-level data model that incorporates the extensions to the original ER model. Enhanced E-R (EER) Model Enhanced ERD are high level models that represent the requirements and complexities of complex database.
- 5. WRAP UP Presented By: Dr. Rosemarie S. Guirre | IS-DBS 313-2 an entity that can be divided into further subtype SUB CLASSES AND SUPER CLASS often called as generalized class SUPER CL ASS SUB CLASS group of entities with some unique attributes. often called as specialized class best understood by “IS-A analysis”
- 6. WRAP UP Presented By: Dr. Rosemarie S. Guirre | IS-DBS 313-2 process of identifying subsets of an entity that share some different characteristic (Top down process) SPECIALIZATION AND GENERALIZATION SPECIALIZ ATI ON GENERALI ZA TIO N process of generalizing an entity which contains generalized attributes or properties of generalized entities. (Bottom up process)
- 7. WRAP UP Presented By: Dr. Rosemarie S. Guirre | IS-DBS 313-2 SPECIALIZATION AND GENERALIZATION SUPER CL ASS SUB CLASS SUB CLASS SUPER CL ASS SUB CLASS SUB CLASS SUPER CL ASS SUB CLASS SUPER CL ASS SUB CLASS SUPER CL ASS SUPER CL ASS SUPER CL ASS SUB CLASS SUB CLASS
- 8. WRAP UP Presented By: Dr. Rosemarie S. Guirre | IS-DBS 313-2 SPECIALIZATION AND GENERALIZATION vehicle car truck motorcycle IS A GENERALIZATION Bottom Up Approach SPECIALIZATION Top Down Approach
- 9. WRAP UP Presented By: Dr. Rosemarie S. Guirre | IS-DBS 313-2 SPECIALIZATION AND GENERALIZATION Technician IS-A Employee Laptop IS-A Computer Faculty IS-A Employee Admin Staff IS-A Employee Tablet IS-A Computer Desktop IS-A Computer
- 10. WRAP UP Presented By: Dr. Rosemarie S. Guirre | IS-DBS 313-2 SPECIALIZATION AND GENERALIZATION employee technician faculty admin_staff IS A GENERALIZATION Bottom Up Approach SPECIALIZATION Top Down Approach
- 11. WRAP UP Presented By: Dr. Rosemarie S. Guirre | IS-DBS 313-2 SPECIALIZATION AND GENERALIZATION Technician IS-A Employee Laptop IS-A Computer Faculty IS-A Employee Admin Staff IS-A Employee Tablet IS-A Computer Desktop IS-A Computer
- 12. WRAP UP Presented By: Dr. Rosemarie S. Guirre | IS-DBS 313-2 SPECIALIZATION AND GENERALIZATION computer laptop tablet desktop IS A GENERALIZATION Bottom Up Approach SPECIALIZATION Top Down Approach
- 13. Presented By: Dr. Rosemarie S. Guirre | IS-DBS 213-3 Sub Class RECAPITULATION Super Class Specialized Class Generalized Class
- 14. WRAP UP SUBCLASS VS. SUPERCLASS Technician IS-A Employee Laptop IS-A Computer Faculty IS-A Employee Admin Staff IS-A Employee Tablet IS-A Computer Desktop IS-A Computer Presented By: Dr. Rosemarie S. Guirre | IS-DBS 213-3
- 15. Presented By: Dr. Rosemarie S. Guirre | IS-DBS 313-2 owner vehicle house computer OWNER Subset of super class Vehicle, house and computer SYMBOL FOR UNION UNION Set of Libray Members relationship indicates either type CATEGORY OR UNION
- 16. Presented By: Dr. Rosemarie S. Guirre | IS-DBS 313-3 AGGREGATIO N allows relationship between relationship and to eliminate redundancy treat relationship set as an abstract entry (abstraction of a relationship into a new entry) DIAGRAM FOR AGGREGATION
- 17. Presented By: Dr. Rosemarie S. Guirre | IS-DBS 313-3 AGGREGATIO N works_on employee job branch manages manager AGGREGATION Eliminate redundancy
- 18. Presented By: Dr. Rosemarie S. Guirre | IS-DBS 313-3 AGGREGATIO N works_on employee job branch manages manager AGGREGATION Eliminate redundancy
- 19. Presented By: Dr. Rosemarie S. Guirre | IS-DBS 313-3 AGGREGATIO N works_on employee job branch manages manager AGGREGATION Eliminate redundancy
- 20. Presented By: Dr. Rosemarie S. Guirre | IS-DBS 313-3 AGGREGATIO N works_on employee job branch manages manager ER MODEL NO relationship to relationship connection
- 21. Presented By: Dr. Rosemarie S. Guirre | IS-DBS 313-3 AGGREGATIO N works_on employee job branch manages manager AGGREGATION Connects relationship without abstraction
- 22. Prepared By: Dr. Rosemarie S. Guirre | IS-DBS 313-2 END OF MODULE 3
Editor's Notes
- Today time the complexity of the data is increasing so it becomes more and more difficult to use the traditional ER model for database modeling. To reduce this complexity of modeling we have to make improvements or enhancements were made to the existing ER model to make it able to handle the complex application in a better way.
- Today time the complexity of the data is increasing so it becomes more and more difficult to use the traditional ER model for database modeling. To reduce this complexity of modeling we have to make improvements or enhancements were made to the existing ER model to make it able to handle the complex application in a better way. SUB CLASS - Sub class inherits the properties and attributes from super class. Following statements hopefully makes some sense to your mind “Technician IS-A Employee”, “Laptop IS-A Computer”.
- Specialization is a process of identifying subsets of an entity that share some different characteristic. It is a top down approach in which one entity is broken down into low level entity. Generalization is a process of generalizing an entity which contains generalized attributes or properties of generalized entities.
- best understood by “IS-A analysis” (subclass) often called as specialized class(subclass) an entity that can be divided into further subtype (superclass) (Bottom up process) (superclass) process of identifying subsets of an entity that share some different characteristic (subclass) Specialization is a process of identifying subsets of an entity that share some different characteristic. It is a top down approach in which one entity is broken down into low level entity. Generalization is a process of generalizing an entity which contains generalized attributes or properties of generalized entities.
- Specialization (Subclass) In above example Vehicle entity can be a Car, Truck or Motorcycle. Generalization (super class) It is a Bottom up process i.e. consider we have 3 sub entities Car, Truck and Motorcycle. Now these three entities can be generalized into one super class named as Vehicle. SPECIALIZATION It is a top down approach in which one entity is broken down into low level entity. In above example Vehicle entity can be a Car, Truck or Motorcycle.
- SUB CLASS- IS-A analysis Following statements hopefully makes some sense to your mind “Technician IS-A Employee”, “Laptop IS-A Computer”.
- This example instance of “sub-class” relationships. Here we have four sets of employees: Secretary, Technician, and Engineer. The employee is super-class of the rest three sets of individual sub-class is a subset of Employee set.
- SUB CLASS- IS-A analysis Following statements hopefully makes some sense to your mind “Technician IS-A Employee”, “Laptop IS-A Computer”.
- Specialization In above example Vehicle entity can be a Car, Truck or Motorcycle. Generalization It is a Bottom up process i.e. consider we have 3 sub entities Car, Truck and Motorcycle. Now these three entities can be generalized into one super class named as Vehicle. SPECIALIZATION It is a top down approach in which one entity is broken down into low level entity. In above example Vehicle entity can be a Car, Truck or Motorcycle.
- SUPER CLASS an entity that can be divided into further subtype often called as generalized class SUB CLASS group of entities with some unique attributes. often called as specialized class (SPECIALIZATION) best understood by “IS-A analysis” SPECIALIZATION (process of generalizing an entity which contains generalized attributes or properties of generalized entities. (Bottom up process) GENERALIZATION process of generalizing an entity which contains generalized attributes or properties of generalized entities. (Bottom up process)
- SUB CLASS- IS-A analysis Following statements hopefully makes some sense to your mind “Technician IS-A Employee”, “Laptop IS-A Computer”.
- Relationship of one super or sub class with more than one super class (Bottom up process). https://www.geeksforgeeks.org/enhanced-er-model/
- AGGREGATION= allows relationship between relationship and to eliminate redundancy Treat relationship set as an abstract entry (abstraction of a relationship into a new entry. Employee works_on different job or different branch of the company We want now to express the task performed by an employee might have a manager assigned.
- Entity=>manager, employee, branch and job Manager->manages->works_on->many employees
- Entity=>manager, employee, branch and job
- Entity=>manager, employee, branch and job
- Entity=>manager, employee, branch and job
- Entity=>manager, employee, branch and job