[Solved] What does the ON UPDATE CASCADE option do in a foreign key constraint? — Ans: Automatically updates child rows when the parent key changes. | SQL

SQL - Table Constraints

What does the ON UPDATE CASCADE option do in a foreign key constraint?

ADeletes child rows when the parent key changes.

BAutomatically updates child rows when the parent key changes.

CPrevents any update on the parent key if child rows exist.

DSets child foreign key values to NULL when the parent key changes.

Step-by-Step Solution

Solution:

Step 1: Understand ON UPDATE CASCADE behavior
ON UPDATE CASCADE means if the parent key changes, the child foreign keys update automatically to match.
Step 2: Compare options with definition
Only Automatically updates child rows when the parent key changes. describes automatic update of child rows on parent key change.
Final Answer:
Automatically updates child rows when the parent key changes. -> Option B
Quick Check:
ON UPDATE CASCADE = automatic child update [OK]

Quick Trick: CASCADE means child rows change with parent keys [OK]

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What does the ON UPDATE CASCADE option do in a foreign key constraint?