Stage 5: Derive the logical data model
Knobit of Data modelling · K-567 · Knowledge
Explains relationship cardinality and optionality
What it means
Minimum and maximum participation of each end of a relationship, read in both directions.
How it is assessed
States the cardinality and optionality of sample relationships in both directions from their rules
Builds on
- None
Needed by
- Recognises a mandatory attribute without its moment of obligationK-112 · Skill
- Recognises a cardinality rule stated from one end onlyK-318 · Skill
- Recognises an unresolved many-to-many relationshipK-521 · Skill
- Recognises a polymorphic associationK-522 · Skill
- Recognises a redundant relationshipK-526 · Skill
- Recognises a relationship contradicting its data ruleK-529 · Skill
- Recognises a check weaker than its ruleK-711 · Skill
- Resolves a many-to-many relationship into an associative entityK-534 · Skill
- Explains the connection, fan and chasm trapsK-569 · Knowledge
- Explains referential integrity and referential actionsK-653 · Knowledge