Which of the following is the correct way to write a subquery with IN in the WHERE clause in PostgreSQL?

easy📝 Syntax Q3 of 15

PostgreSQL - Subqueries in PostgreSQL

Which of the following is the correct way to write a subquery with IN in the WHERE clause in PostgreSQL?

ASELECT * FROM orders WHERE product_id IN (SELECT id FROM products WHERE price > 100);

BSELECT * FROM orders WHERE product_id = IN (SELECT id FROM products WHERE price > 100);

CSELECT * FROM orders WHERE product_id IN SELECT id FROM products WHERE price > 100;

DSELECT * FROM orders WHERE product_id IN (SELECT id FROM products WHERE price > 100

Step-by-Step Solution

Solution:

Step 1: Identify correct syntax for subquery with IN
The subquery must be enclosed in parentheses and follow the IN keyword directly.
Step 2: Analyze options
SELECT * FROM orders WHERE product_id IN (SELECT id FROM products WHERE price > 100); correctly uses parentheses and proper syntax.
SELECT * FROM orders WHERE product_id = IN (SELECT id FROM products WHERE price > 100); has an extra '=' sign.
SELECT * FROM orders WHERE product_id IN SELECT id FROM products WHERE price > 100; misses parentheses around the subquery.
SELECT * FROM orders WHERE product_id IN (SELECT id FROM products WHERE price > 100 is missing the closing parenthesis.
Final Answer:
Option A -> Option A
Quick Check:
Subquery must be inside parentheses after IN [OK]

Quick Trick: Always enclose subqueries in parentheses after IN [OK]

Common Mistakes:

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