[Solved] Which of the following is the correct syntax for an INNER JOIN in PostgreSQL? — Ans: SELECT * FROM table1 INNER JOIN table2 ON table1.id = table2.id; | PostgreSQL

PostgreSQL - Joins in PostgreSQL

Which of the following is the correct syntax for an INNER JOIN in PostgreSQL?

ASELECT * FROM table1 INNER JOIN table2 ON table1.id = table2.id;

BSELECT * FROM table1 INNER JOIN table2 WHERE table1.id = table2.id;

CSELECT * FROM table1 INNER JOIN table2 USING (id);

DSELECT * FROM table1 JOIN table2 ON table1.id == table2.id;

Step-by-Step Solution

Solution:

Step 1: Review INNER JOIN syntax
The correct syntax uses INNER JOIN with ON clause specifying the join condition using a single equals sign (=).
Step 2: Check each option
SELECT * FROM table1 INNER JOIN table2 ON table1.id = table2.id; uses correct INNER JOIN syntax with ON and =. SELECT * FROM table1 INNER JOIN table2 WHERE table1.id = table2.id; missing ON or USING clause, syntax error. SELECT * FROM table1 INNER JOIN table2 USING (id); uses correct USING syntax with parentheses. SELECT * FROM table1 JOIN table2 ON table1.id == table2.id; uses double equals (==) which is invalid in SQL.
Final Answer:
SELECT * FROM table1 INNER JOIN table2 ON table1.id = table2.id; -> Option A
Quick Check:
INNER JOIN uses ON with = [OK]

Quick Trick: Use ON with single = for INNER JOIN conditions [OK]

Common Mistakes:

Master "Joins in PostgreSQL" in PostgreSQL

9 interactive learning modes - each teaches the same concept differently

Which of the following is the correct syntax for an INNER JOIN in PostgreSQL?