(e) Referential integrity.

Question 1

What is referential integrity?

Answer 1

A rule ensuring foreign keys match valid primary keys in another table.

Question 2

What happens if referential integrity is not maintained?

Answer 2

Orphan records can appear, breaking data consistency.

Question 3

What is an ‘orphan record’?

Answer 3

A record whose foreign key value references a non-existent primary key value

Question 4

How can referential integrity be enforced in SQL?

Answer 4

By declaring foreign key constraints (e.g., FOREIGN KEY REFERENCES).