The values appearing in given attributes of any tuple in the referencing…
2023
The values appearing in given attributes of any tuple in the referencing relation must likewise occur in specified attributes of at least one tuple in the referenced relation, according to _____ integrity constraint.
- A.
referential
- B.
primary
- C.
referencing
- D.
More than one of the above
- E.
None of the above
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Correct answer: A
Key idea: Referential integrity controls the relationship between a referencing relation and a referenced relation.
Referencing relation: contains the foreign-key value.
Referenced relation: contains the matching primary/candidate-key value.
Rule: a foreign-key value must either be null where allowed or match an existing referenced key value.
Answer: referential integrity constraint