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Understanding The Relational Model in Databases

Explore the key concepts of relational databases including keys, integrity constraints, base relations, and views. Learn about entities, domains, tuples, and the importance of data integrity.

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Understanding The Relational Model in Databases

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  1. Chapter 3 The Relational Model

  2. Agenda • Concept • Property • Key • Integrity Constraint • Base Relation & View

  3. Concept • Relation • Attribute • Domain • Tuple • Degree • Cardinality • Relational Database

  4. Property • Unique relation name • Unique attribute • No duplication tuples • No repeating group (single value for an attribute) • Same domain for an attribute • Insignificance of the tuples or attributes order

  5. Key • Superkey • Candidate key (Alternative key) • Primary key • Foreign key

  6. Integrity Constraint • Null • Integrity constraint • Entity • Reference • Domain (edit or field) • Enterprise (business rule)

  7. Base Relation & View • Base relation • A named relation of an entity in conceptual schema • Tuples stored in physical database • View • Virtual relation • Dynamic generated for end user • Not stored in the physical database • Purpose of views • Security • User friendly report • Performance

  8. Points To Remember • Concept • Property • Key • Integrity Constraint • Base Relation & View

  9. Assignment • Review chapters 1-3, & appendix c • Read Chapter 4 (skip relational calculus 4.2) • Do Exercise 3.8 • Due date:

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