'Partial specialization rule' diaporamas de présentation

Chapter 4 The Enhanced E-R Model and Business Rules

Chapter 4 The Enhanced E-R Model and Business Rules. Supertypes and Subtypes. Subtype: A subgrouping of the entities in an entity type which has attributes that are distinct from those in other subgroupings.

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Enhanced Entity-Relationship Modeling

Enhanced Entity-Relationship Modeling. Strong and Weak Entity Types. Strong entity: Each object is uniquely identifiable using primary key of that entity type. Weak entity: Each object cannot be uniquely identified using only the attributes associated with that entity type.

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Chapter 4: The Enhanced E-R Model and Business Rules

Chapter 4: The Enhanced E-R Model and Business Rules. Modern Database Management 6 th Edition Jeffrey A. Hoffer, Mary B. Prescott, Fred R. McFadden. Supertypes and Subtypes.

596 views • 31 slides

The Enhanced Entity Relationship Diagrams (E-ERDs)

The Enhanced Entity Relationship Diagrams (E-ERDs). Supertypes and Subtypes. Subtype: A subgrouping of the entities in an entity type that has attributes distinct from those in other subgroupings Supertype: A generic entity type that has a relationship with one or more subtypes

771 views • 28 slides

315 views • 12 slides