CSE2DBF Database EERD Proof Reading Services

CSE2DBF Database EERD Proof Reading Services

Enhanced Entity Relationship Diagram

The following EERD is drawn on the case study mentioned. The entities drawn out here are as follows:

1. Store

2. Department

3. Employee

4. Employee Type

5. Employee Category

6. Casual Employee

7. Part-Time Employee

8. Full-Time Employee

9. Local Employee

10. Central Employee

11. Shareholder

12. Account

13. Franchise Team

14. Application

15. Sales Report

16. Brand

17. Item

The relationship between store and department is one to many as one store can have many departments (total participation of both the entities). The min-max is (1, N) from the store side and (1, 1) from the department side.

The relationship between department and employee is one to many as one department can have many employees(total participation of both the entities).The min-max is (1, N) from the department side and (1, 1) from the employee side.

The specialization of an employee is employee type and employee category. Casual Employee, Part-time employee and full time form a union relationship to employee type. Local Employee and Central employee form a union to Employee category.

There is a one on one relationship from department to account as each department has one account (total participation of both the entities). The min-max is (1, 1) from the department side and (1, 1) from the store side.

Each department is managed by a Franchise team, bringing one on one relationship (total participation of both the entities). The min-max is (1, 1) from the department side and (1, 1) from the Franchise team side.

Shareholder and Full-time employee can apply for Franchise team bringing one to one relationship from Shareholder to Franchise team and from Full-time employee to Franchise team (partial participation of Full-time employee and Shareholder).The min-max is (0, 1) from the Full-time employee and Shareholder side and (1, N) from the Franchise team side.

 Each franchise team can lodge much application, bringing one to many relationships from Franchise team to the application (total participation of both the entities). The min-max is (1, N) from the Franchise team side and (1, 1) from the application side.

Each department can make many sales reports (total participation of both the entities) (min-max is (1, N) on both the sides), each brand can have many items (total participation of both the entities)(min-max is (1, N) on both the sides), one item can be mentioned in many sales reports (total participation of both the entities) (min-max is (1, N) from the item side and (1, 1) from the sales report side) and one brand can be sold and mentioned in many sales reports (total participation of both the entities)(min-max is (1, N) on both the sides), bringing one to many relationships. The employee makes sales of the items; one employee can sell many items to win the employee of the week bringing one to many relationships (min-max is (1, N) on both the sides) from employee to the item (total participation of both the entities).

Assumptions

1. We have taken an entity named as Item which is the item being sold having attributes Item_id, Item_number and Item_name.

2. We have taken an entity named Brand whose attributes are Brand_id and Brand_name.

3. The relationship between brand and item is that every brand has a number of items.

References

Lucidchart. (2018). Enhanced ER Diagram Tutorial. Retrieved from https://www.lucidchart.com/pages/enhanced-entity-relationship-diagram
Tutorial Ride. (2017).Enhanced Entity Relationship Model (EER Model). Retrieved fromhttps://www.tutorialride.com/dbms/enhanced-entity-relationship-model-eer-model.htm