CS340 · Chapter 3 · Annotated SlidesThe Enhanced ER (EER) Model
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Overview

The Enhanced ER (EER) Model

Subclasses and superclasses, attribute inheritance, specialization and generalization, attribute-defined specialization, disjoint vs. overlapping and total vs. partial constraints, hierarchies and lattices, categories (union types) and aggregation.

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Every original slide is shown unchanged. Yellow marks on a slide point to a numbered note: hover or tap a mark to jump to its note, and hover a note to see its marks. Questions tagged Past exam appeared on a real paper; Prediction questions are likely angles, not confirmed. Pick an answer to each question: a wrong pick tells you why it is wrong, so you can try again.

All 46 slides
  1. 1 The Enhanced Entity–Relationship (EER) Model
  2. 2 LEARNING GOALS
  3. 3 DATABASES SO FAR
  4. 4 TOPICS DISCUSSED IN CHAPTER 3
  5. 5 EER
  6. 6 CHAPTER OUTLINE
  7. 7 SUB CLASSES AND SUPER CLASSES
  8. 8 SUB CLASSES AND SUPER CLASSES
  9. 9 SUB CLASSES AND SUPER CLASSES
  10. 10 SUB CLASSES AND SUPER CLASSES
  11. 11 SUB CLASSES AND SUPER CLASSES
  12. 12 SUB CLASSES AND SUPER CLASSES
  13. 13 BASIC NOTATION
  14. 14 ATTRIBUTE INHERITANCE IN SUPERCLASS / SUBCLASS RELATIONSHIPS
  15. 15 WHEN IS IT NECESSARY TO INCLUDING SUPERCLASS/SUBCLASS RELATIONSHIP?
  16. 16 SPECIALIZATION
  17. 17 GENERALIZATION
  18. 18 GENERALIZATION
  19. 19 GENERALIZATION
  20. 20 ATTRIBUTE-DEFINED SPECIALIZATION IN EER DIAGRAMS
  21. 21 DISPLAYING AN ATTRIBUTE- DEFINED SPECIALIZATION IN EER DIAGRAMS
  22. 22 CONSTRAINTS ON SPECIALIZATION AND GENERALIZATION
  23. 23 CONSTRAINTS ON SPECIALIZATION AND GENERALIZATION
  24. 24 it
  25. 25 CONSTRAINTS ON SPECIALIZATION & GENERALIZATION
  26. 26 EXAMPLE OF DISJOINT & TOTAL PARTICIPATION
  27. 27 EXAMPLE OF DISJOINT & PARTIAL PARTICIPATION
  28. 28 EXAMPLE OF OVERLAPPING & TOTAL PARTICIPATION
  29. 29 EXAMPLE OF OVERLAPPING & PARTIAL PARTICIPATION
  30. 30 CONSTRAINTS ON SPECIALIZATION & GENERALIZATION
  31. 31 ANOTHER EXAMPLE OF DISJOINT & OVERLAPPING
  32. 32 HIERARCHIES, LATTICES, & SHARED SUB-CLASSES
  33. 33 HIERARCHIES, LATTICES & SHARED SUB-CLASSES
  34. 34 LATTICE EXAMPLE (UNIVERSITY)
  35. 35 LATTICE EXAMPLE (UNIVERSITY)
  36. 36 CATEGORIES (UNION TYPES)
  37. 37 CATEGORIES (UNION TYPES)
  38. 38 CATEGORIES (OWNER, AND REGISTERED_VE HICLE)
  39. 39 CATEGORIES (OWNER, AND REGISTERED_VE HICLE)
  40. 40 CATEGORIES INHERITANCE
  41. 41 CATEGORIES (UNION TYPES)
  42. 42 ACTIVITY
  43. 43 SOLUTION
  44. 44 AGGREGATIO N (BRIEFLY)
  45. 45 SUMMARY OF EER CONCEPTS
  46. 46 PROJECT FIRST STEPS
Slide 1 / 46

The Enhanced Entity–Relationship (EER) Model

Slide 1: The Enhanced Entity–Relationship (EER) Model
Slide 2 / 46

LEARNING GOALS

Slide 2: LEARNING GOALS
Slide 3 / 46

DATABASES SO FAR

Slide 3: DATABASES SO FAR
Slide 4 / 46

TOPICS DISCUSSED IN CHAPTER 3

Slide 4: TOPICS DISCUSSED IN CHAPTER 3
Slide 5 / 46

EER

Slide 5: EER
Slide 6 / 46

CHAPTER OUTLINE

Slide 6: CHAPTER OUTLINE
Slide 7 / 46

SUB CLASSES AND SUPER CLASSES

Slide 7: SUB CLASSES AND SUPER CLASSES
Slide 8 / 46

SUB CLASSES AND SUPER CLASSES

Slide 8: SUB CLASSES AND SUPER CLASSES
Slide 9 / 46

SUB CLASSES AND SUPER CLASSES

Slide 9: SUB CLASSES AND SUPER CLASSES
Slide 10 / 46

SUB CLASSES AND SUPER CLASSES

Slide 10: SUB CLASSES AND SUPER CLASSES
Slide 11 / 46

SUB CLASSES AND SUPER CLASSES

Slide 11: SUB CLASSES AND SUPER CLASSES
Slide 12 / 46

SUB CLASSES AND SUPER CLASSES

Slide 12: SUB CLASSES AND SUPER CLASSES
Slide 13 / 46

BASIC NOTATION

Slide 13: BASIC NOTATION
Slide 14 / 46

ATTRIBUTE INHERITANCE IN SUPERCLASS / SUBCLASS RELATIONSHIPS

Slide 14: ATTRIBUTE INHERITANCE IN SUPERCLASS / SUBCLASS RELATIONSHIPS
Slide 15 / 46

WHEN IS IT NECESSARY TO INCLUDING SUPERCLASS/SUBCLASS RELATIONSHIP?

Slide 15: WHEN IS IT NECESSARY TO INCLUDING SUPERCLASS/SUBCLASS RELATIONSHIP?
Slide 16 / 46

SPECIALIZATION

Slide 16: SPECIALIZATION
Slide 17 / 46

GENERALIZATION

Slide 17: GENERALIZATION

Notes

  1. Generalization: bottom-up, find a common superclass for existing entity types (CAR, TRUCK → VEHICLE).

Exam angle

PredictionQ1

Combining CAR and TRUCK into a VEHICLE superclass is:

Slide 18 / 46

GENERALIZATION

Slide 18: GENERALIZATION
Slide 19 / 46

GENERALIZATION

Slide 19: GENERALIZATION
Slide 20 / 46

ATTRIBUTE-DEFINED SPECIALIZATION IN EER DIAGRAMS

Slide 20: ATTRIBUTE-DEFINED SPECIALIZATION IN EER DIAGRAMS

Notes

  1. Attribute-defined (predicate-defined) specialization: membership decided by an attribute value (JobType).

Slide 21 / 46

DISPLAYING AN ATTRIBUTE- DEFINED SPECIALIZATION IN EER DIAGRAMS

Slide 21: DISPLAYING AN ATTRIBUTE- DEFINED SPECIALIZATION IN EER DIAGRAMS
Slide 22 / 46

CONSTRAINTS ON SPECIALIZATION AND GENERALIZATION

Slide 22: CONSTRAINTS ON SPECIALIZATION AND GENERALIZATION

Notes

  1. Disjointness: d = disjoint (at most one subclass), o = overlapping (may be in several). Completeness: total (double line, must be in one) or partial.

  2. Memory trick Two independent questions: "can it be in two?" (d/o) and "must it be in one?" (total/partial).

Exam angle

PredictionQ1

A person can be both a STUDENT and an EMPLOYEE, and some people are neither. The specialization is:

Slide 23 / 46

CONSTRAINTS ON SPECIALIZATION AND GENERALIZATION

Slide 23: CONSTRAINTS ON SPECIALIZATION AND GENERALIZATION
Slide 24 / 46

it

Slide 24: it
Slide 25 / 46

CONSTRAINTS ON SPECIALIZATION & GENERALIZATION

Slide 25: CONSTRAINTS ON SPECIALIZATION & GENERALIZATION
Slide 26 / 46

EXAMPLE OF DISJOINT & TOTAL PARTICIPATION

Slide 26: EXAMPLE OF DISJOINT & TOTAL PARTICIPATION
Slide 27 / 46

EXAMPLE OF DISJOINT & PARTIAL PARTICIPATION

Slide 27: EXAMPLE OF DISJOINT & PARTIAL PARTICIPATION
Slide 28 / 46

EXAMPLE OF OVERLAPPING & TOTAL PARTICIPATION

Slide 28: EXAMPLE OF OVERLAPPING & TOTAL PARTICIPATION
Slide 29 / 46

EXAMPLE OF OVERLAPPING & PARTIAL PARTICIPATION

Slide 29: EXAMPLE OF OVERLAPPING & PARTIAL PARTICIPATION
Slide 30 / 46

CONSTRAINTS ON SPECIALIZATION & GENERALIZATION

Slide 30: CONSTRAINTS ON SPECIALIZATION & GENERALIZATION
Slide 31 / 46

ANOTHER EXAMPLE OF DISJOINT & OVERLAPPING

Slide 31: ANOTHER EXAMPLE OF DISJOINT & OVERLAPPING
Slide 32 / 46

HIERARCHIES, LATTICES, & SHARED SUB-CLASSES

Slide 32: HIERARCHIES, LATTICES, & SHARED SUB-CLASSES

Notes

  1. Hierarchy: each subclass has one superclass. Lattice: a shared subclass has several superclasses (multiple inheritance).

Exam angle

PredictionQ1

A STUDENT_ASSISTANT that is both an EMPLOYEE and a STUDENT is a:

Slide 33 / 46

HIERARCHIES, LATTICES & SHARED SUB-CLASSES

Slide 33: HIERARCHIES, LATTICES & SHARED SUB-CLASSES
Slide 34 / 46

LATTICE EXAMPLE (UNIVERSITY)

Slide 34: LATTICE EXAMPLE (UNIVERSITY)
Slide 35 / 46

LATTICE EXAMPLE (UNIVERSITY)

Slide 35: LATTICE EXAMPLE (UNIVERSITY)
Slide 36 / 46

CATEGORIES (UNION TYPES)

Slide 36: CATEGORIES (UNION TYPES)

Notes

  1. Category (union type): a subclass of the UNION of different superclasses (OWNER is a PERSON or BANK or COMPANY). Inherits from only the one it belongs to.

  2. Trap Shared subclass = in ALL its superclasses (intersection). Category = in ONE of them (union).

Slide 37 / 46

CATEGORIES (UNION TYPES)

Slide 37: CATEGORIES (UNION TYPES)
Slide 38 / 46

CATEGORIES (OWNER, AND REGISTERED_VE HICLE)

Slide 38: CATEGORIES (OWNER, AND REGISTERED_VE HICLE)
Slide 39 / 46

CATEGORIES (OWNER, AND REGISTERED_VE HICLE)

Slide 39: CATEGORIES (OWNER, AND REGISTERED_VE HICLE)
Slide 40 / 46

CATEGORIES INHERITANCE

Slide 40: CATEGORIES INHERITANCE
Slide 41 / 46

CATEGORIES (UNION TYPES)

Slide 41: CATEGORIES (UNION TYPES)
Slide 42 / 46

ACTIVITY

Slide 42: ACTIVITY
Slide 43 / 46

SOLUTION

Slide 43: SOLUTION
Slide 44 / 46

AGGREGATIO N (BRIEFLY)

Slide 44: AGGREGATIO N (BRIEFLY)

Notes

  1. Aggregation: treat a relationship as a higher-level entity so it can join other relationships.

Slide 45 / 46

SUMMARY OF EER CONCEPTS

Slide 45: SUMMARY OF EER CONCEPTS
Slide 46 / 46

PROJECT FIRST STEPS

Slide 46: PROJECT FIRST STEPS