LU03.L02 - Designing an ERM

For this scenario, the following entity-types are identified:

1. Country

• Attributes
  • CountryID (Primary Key)
  • CountryName
  • ContinentName

2. Trip

• Attributes
  • TripID (Primary Key)
  • CountryID (Foreign Key)
  • StartDate
  • EndDate
  • Price
• Relationships:
  • Country: A trip occurs in one country.
  • Duration: Calculated as the difference between EndDate and StartDate.

3. Continent

• Attributes:
  • ContinentID (Primary Key)
  • ContinentName
• Relationships:
  • Country: Each country is located on one continent.

4. Relationships:

• One-to-Many:
  • A Continent can have many Countries.
  • A Country can have many Trips.

5. ERD in Crow's feet notation Continent (1) ————< has >———— (∞) Country Country (1) ————< hosts >———— (∞) Trip

Volkan Demir