What is a key risk when deleting rows referenced by foreign keys in SQL?
2025
What is a key risk when deleting rows referenced by foreign keys in SQL?
Answer: D. Orphaned child records if ON DELETE CASCADE isn't used — When you delete a row from a parent table that is actively referenced by a foreign key in a child table, you risk breaking referential integrity. If the…
- A.
Automatic table encryption
- B.
Duplicate primary keys
- C.
Improved query performance
- D.
Orphaned child records if ON DELETE CASCADE isn't used
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Correct answer: D
When you delete a row from a parent table that is actively referenced by a foreign key in a child table, you risk breaking referential integrity.
If the database schema does not explicitly block the deletion (e.g., via a RESTRICT or NO ACTION constraint) or automatically clean up the child table using a referential action like ON DELETE CASCADE, the rows in the child table will lose their valid parent association. These left-behind rows are known as orphaned child records, meaning they contain a foreign key value pointing to a parent record that no longer exists.