[Solved] What is the main purpose of a FOREIGN KEY constraint in a database? — Ans: To link two tables by ensuring values in one table match values in another | SQL

SQL - Table Constraints

What is the main purpose of a FOREIGN KEY constraint in a database?

ATo store large amounts of text data efficiently

BTo speed up database queries by creating indexes

CTo link two tables by ensuring values in one table match values in another

DTo automatically backup the database

Step-by-Step Solution

Solution:

Step 1: Understand the role of FOREIGN KEY
A FOREIGN KEY connects columns in two tables to keep data related and consistent.
Step 2: Compare options with this role
Only To link two tables by ensuring values in one table match values in another describes linking tables by matching values, which is the purpose of FOREIGN KEY.
Final Answer:
To link two tables by ensuring values in one table match values in another -> Option C
Quick Check:
FOREIGN KEY links tables = A [OK]

Quick Trick: FOREIGN KEY links tables by matching columns [OK]

Common Mistakes:

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What is the main purpose of a FOREIGN KEY constraint in a database?