Study
CS-315 route
Unit 3 · Lesson 3 of 4 11 min

The Enhanced Entity-Relationship (EER) Model

Every lecturer and every cleaner is staff, but only one of them has a research area, and the model should know that.

What this unit covers

Unit 3: Entity-Relationship Modelling

  1. 1 Entities, Attributes and Keys in the ER ModelBefore a single table exists, sketch the things the business cares about and what it needs to know about each. · 12 min
  2. 2 Relationship Types, Cardinality Ratios and Participation ConstraintsThe lines between the boxes carry the business rules, such as one doctor many patients, or no ward without a hospital. · 12 min
  3. 3 The Enhanced Entity-Relationship (EER) ModelEvery lecturer and every cleaner is staff, but only one of them has a research area, and the model should know that. · 11 min
  4. 4 Mapping an ER Schema to RelationsSeven mechanical rules turn every box, diamond and oval into tables, keys and foreign keys. · 13 min