1. Database Processing: David M. Kroenke’s Chapter Five:
Fundamentals, Design, and Implementation
Chapter Five:
Data Modeling with the
Entity-Relationship Model
Part Two
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

2. Strong Entity Patterns: 1:1 Strong Entity Relationships
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

3. Strong Entity Patterns: 1:1 Strong Entity Relationships
---- Non-identifying relationship, 0:0, 1:1 (min, max)
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

4. Strong Entity Patterns: 1:N Strong Entity Relationships
Although this appears to be clearly 1:N, You can’t be sure that a department is in a single company because this form doesn’t show the relationship. ASK the user. OK, the user thinks … ask the student.
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

5. Strong Entity Patterns: 1:N Strong Entity Relationships
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

6. Strong Entity Patterns: N:M Strong Entity Relationships
Again this seems to be a 1:N relationship but …
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

7. Strong Entity Patterns: N:M Strong Entity Relationships
… here we see a report from the other perspective. Here the form and report together let us know that there is an N:M relationship.
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

8. Strong Entity Patterns: N:M Strong Entity Relationships
Part should have a 0 above the crow’s foot. Note is provided due to ERWins deficiency
Company-Department is a Strong Entity relationship, where as Company-Part is an ID-dependent relationship.
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

9. ID-Dependent Relationships: The Association Pattern
Note the Price column, which has been added.
Includes Parts
Includes companies
Quotation is ID-dependent on both PART and COMPANY! It is not just a simple relation because it includes price!
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

10. ID-Dependent Relationships: The Association Pattern
This is equivalent to saying that a Part must have a “PRICE”, but a company may not sell it.
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

11. ID-Dependent Relationships: The Multivaled Attribute Pattern
Classical multivalue dependency
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

12. ID-Dependent Relationships: The Multivaled Attribute Pattern
Company:Phone 1:0, 1:N
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

13. ID-Dependent Relationships: The Multivaled Attribute Pattern
N-Multivalued attributes breeds multiple ID-Dependent Entities
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

14. ID-Dependent Relationships: The Multivaled Attribute Pattern
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

15. ID-Dependent Relationships: The Archtype/Instance Pattern
The archtype/instance pattern occurs when the ID-dependent child entity is the physical manisfestation (instance) of an abstract or logical parent:
PAINTING : PRINT
CLASS : SECTION
YACHT_DESIGN : YACHT
HOUSE_MODEL: HOUSE
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

16. ID-Dependent Relationships: The Archtype/Instance Pattern
Note that these are true ID-dependent relationships - the identifier of the parent appears as part of the composite identifier of the ID-dependent child.
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

17. ID-Dependent Relationships: The Archtype/Instance Pattern
Note the use of weak, but not ID-dependent children.
Just because the ID:ClassName isn’t stated doesn’t mean there isn’t a way to determine it from the data. ClassDays, Time, Professor, SectionNumber are sufficient to identify the class!
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall

18. David M. Kroenke’s Database Processing Fundamentals, Design, and Implementation (10th Edition)
End of Presentation:
Chapter Five Part Two
DAVID M. KROENKE’S DATABASE PROCESSING, 10th Edition
© 2006 Pearson Prentice Hall