Week 4: Entity-Relationship Model

Due: Wednesday, Sep 16th

We start drawing ER diagrams on Tuesday and continue on Thursday. Tuesday needs only the idea of an entity and an attribute, so do not worry if you have not finished this reading by then. Arrive Thursday knowing the rest of the vocabulary, so that class time goes to drawing rather than to definitions.

Prompt

Paste the standard prompt, then paste this block.

Topic: Entity-relationship modeling.

My learning objectives:
- Define entity, attribute, relationship, cardinality, and
  participation.
- Read an ER diagram and describe the rules that the diagram
  encodes about the data.
- Identify the entities and relationships in a written
  description of a system.

Teach me these concepts. Give me an analogy or a comparison
before you give me the definition, and don't move on until I
have restated the idea in my own words.

Sources

• 2.1 Introduction to data modeling
• 2.2 Entity-relationship diagrams

Notation

There are several notations for ER diagrams, and assistants tend to mix them. In this course we use Chen notation for conceptual models, which is what we will draw this week. If your assistant draws something that looks different from what the book shows, ask which notation it is using.