Sep 17: Relationships and Cardinality

Learning Objectives

After today's class, you should be able to:

• Explain the pull request workflow: team branches, cross-team review, and protected main.
• Draw relationships in Chen notation with correct cardinality and participation.

Lesson Outline

Class Repository [25 min]

• GitHub Workflow – read this one carefully
• Clone the repository, then pip install -e . from the top of it
  • This is the step that silently breaks every import if you skip it
• Directory tour: src/planner/core/ is provided, your team owns one directory
• Your team's branch for GP1 already exists – commit there, open a pull request by Monday
• Peer review: another team reviews your pull request, and I merge (likely on Sep 24)

Lecture Slides [15 min]

• Debrief Week 4 reading (concept mode)
• ER Models
  • Relationships, cardinality, and participation

Lab Activity [25 min]

• Abstract ER Models, Part 2
• Extend Tuesday's diagram; do not start over

Group Project [10 min]

• Questions about Project 1 (due Sep 21)
• Has everyone cloned the repository and installed the package?

Your To-Do List

• Submit GP1 – commit to your team branch and open a pull request ← due Monday