[Solved] What is the primary effect of using an INNER JOIN between two tables in PostgreSQL? — Ans: It returns only rows with matching values in both tables. | PostgreSQL

PostgreSQL - Joins in PostgreSQL

What is the primary effect of using an INNER JOIN between two tables in PostgreSQL?

AIt returns all rows from the second table regardless of matches.

BIt returns all rows from the first table regardless of matches.

CIt returns only rows with matching values in both tables.

DIt returns all rows from both tables, including unmatched rows.

Step-by-Step Solution

Solution:

Step 1: Understand INNER JOIN behavior
INNER JOIN returns rows where the join condition matches in both tables.
Step 2: Compare options
Only It returns only rows with matching values in both tables. correctly states that only matching rows are returned.
Final Answer:
It returns only rows with matching values in both tables. -> Option C
Quick Check:
INNER JOIN filters to matching rows only. [OK]

Quick Trick: INNER JOIN returns only matching rows from both tables. [OK]

Common Mistakes:

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What is the primary effect of using an INNER JOIN between two tables in PostgreSQL?