Lesson Plan

• Describe the purpose and key characteristics of primary keys.
• Explain how foreign keys establish relationships and enforce referential integrity.
• Compare primary and foreign keys across aspects such as uniqueness, nullability, and location.
• Apply rules for defining stable primary keys and appropriate foreign keys in a database design.
• Identify common mistakes and propose corrective actions when designing keys.

• Projector or interactive whiteboard
• Slides outlining key concepts
• Sample database schema handout (Students & Enrollments)
• Laptop with SQL client (e.g., MySQL Workbench)
• Worksheet with key‑identification exercises
• Whiteboard markers

Begin with a quick question: “What uniquely identifies a student in a school system?” Connect this to prior knowledge of tables and records. Explain that today’s success criteria are to differentiate primary and foreign keys, describe their properties, and apply them in a simple database design.

1. Do‑now (5'): Quick quiz on database terminology (primary key, foreign key).
2. Teacher input (10'): Present definitions and characteristics using slides and a comparison table.
3. Guided practice (15'): Walk through the Students‑Enrollments example, identifying primary and foreign keys on the handout.
4. Collaborative activity (15'): In pairs, design a two‑table schema, decide on primary and foreign keys, and record decisions on the worksheet.
5. Check for understanding (10'): Mini‑quiz via Kahoot or an exit ticket with three targeted questions.
6. Summary & reflection (5'): Recap key points, address any misconceptions, and preview the next topic.

Summarise that primary keys uniquely identify records while foreign keys create links between tables, ensuring data integrity. Ask students to write one takeaway on a sticky note as an exit ticket. Assign a homework task to create a three‑table diagram with appropriate primary and foreign keys.