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Ryan 2023-06-14 14:40:28 +08:00
parent 0220f8f050
commit 6de38c5f71

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@ -961,6 +961,20 @@
- LATER EER
- Most useful additional concept of EER model:
specialization/generalization.
- Specialization
- Process of maximizing differences between
members of an entity by identifying their
distinguishing characteristics.
- Generalization
- Process of minimizing differences between
entities by identifying their common
characteristics.
- Two constraints that may apply to a
specialization/generalization:
- participation constraints
- May be {{c1 mandatory}} or {{c1 optional}}.
- disjoint constraints
- Superclass / Subclass
- Superclass :-> An entity type that includes one or more distinct
id:: 64895f2f-b868-46ec-9d80-7079eaf3197d
subgroupings of its occurrences.
@ -974,19 +988,6 @@
- Subclass :-> A distinct subgrouping of occurrences of an entity
id:: 64895f39-d886-436b-9afe-ba75d37c8b45
type.
- Specialization
- Process of maximizing differences between
members of an entity by identifying their
distinguishing characteristics.
- Generalization
- Process of minimizing differences between
entities by identifying their common
characteristics.
- Two constraints that may apply to a
specialization/generalization:
- participation constraints
- disjoint constraints
-
- LATER designing ER diagram
- DONE Block 3
collapsed:: true