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For this assignment, you will use, as a starting point, the entity relationship diagrams you created for your Facebook or Twitter account in Homework 1. Your task is to represent Facebook/Twitter accounts with an ER diagram using the UML notation.

Your final ER diagram must include the following elements:

? Entities, attributes, and relationships between entities

? Primary and foreign keys

? Type of each relationships (such as 0…1, 1…1, 1…*, etc)

? Participation and disjoint constraints

? Superclasses and/or subclasses

Refer to Chapters 13, 16, and 17 for examples of these models. Submit your model as an image file.

In a separate file, also submit your answers to the following questions.

For your model. indicate:

1. Strong entities

2. Weak entities

3. One-to-many relationships

4. One-to-one relationships

5. Many-to-many relationships

6. Multi-valued attributes

7. Composite attributes

8. Derived attributes

9. Candidate keys