Subject: DBMS

Topic: Entity Relationship Model

Draw ER diagram for the given scenario:

Consider a bus ticketing system that records information about the passegner, bus and route. Passenger is assigned to a bus that travels to a route. A  bus contains many passegners and a passegner can be assigned into only one bus. Many busses travel in same route but a bus can travel in only one route. The attributes of passegner are pid(unique), gender and phone_no(multi-values). Similarly bus contains regno(unique) and color and route contains rid(unique), distance and rate.

Explain how aggregation and generalization help to minimize redundancy while designing ER Diagram.

Design a database using ER diagram for a commercial bank. This commercial bank maintains information about entities: Depositor, Account, Loan, and Branch. State any assumptions made in the design of the ER diagram.