Knobit of Data modelling · K-711 · Skill

Recognises a check weaker than its rule

What it means

A check that lets through rows the rule forbids: one direction of a two-way rule, presence where the rule says exactly one, a range with an open end the rule closes, a value set wider than the rule's.

How it is assessed

Flags the deficient case and passes the acceptable one. Deficient: Rule: each account has exactly one IBAN and no IBAN is shared. Check: `account_identifier IS NOT NULL` only. Duplicates pass Acceptable: Two checks: completeness on `account_identifier`, and uniqueness over it. Or the rule split into two at stage 3, each with its check

Builds on

Explains relationship cardinality and optionalityK-567 · Knowledge
Explains traceability from data rule to checkK-752 · Knowledge

Needed by

None