Slide 4

CSCI 201 Guest Lecture: Data Modeling

What is a data model? (cont.)

School Schedule Example

The first example illustrates an algebraic model and the second is an example of a geometric model. This is an example of an entity-relationship model:

Problem: The computer science department has a number of professors who teach various courses, and a number of students who attend various courses. Create a data model to allow a program to keep track of relevant information.

Solution: Represent the model as a graph with entities (nouns) at the nodes (vertices) and relationships (verbs) as directed edges. The nouns are professor, course, and student. The verbs are teach and attend. Draw and label the graph:


Entity-relationship Model

Each entity has a number of attributes. List the attributes under each entity:


Entity-relationship Model with Attributes

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