Stage 3: Document data rules as SBVR fact types and rule statements
Knobit of Data modelling · K-318 · Skill
Recognises a cardinality rule stated from one end only
What it means
A cardinality rule stated from one end, leaving the other end unconstrained. The commonest cause of duplicates.
How it is assessed
Flags the deficient case and passes the acceptable one. Deficient: "Each account has exactly one IBAN" (nothing stops two accounts sharing one) Acceptable: Both: "each account has exactly one IBAN" and "each IBAN is held by at most one account"
Builds on
- Explains relationship cardinality and optionalityK-567 · Knowledge
Needed by
- None