[Solved] Identify the error in this query:SELECT name FROM employees WHERE department_id = SELECT id FROM departments WHERE name = 'Sales'; | PostgreSQL

PostgreSQL - Subqueries in PostgreSQL

Identify the error in this query:

SELECT name FROM employees WHERE department_id = SELECT id FROM departments WHERE name = 'Sales';

AMissing parentheses around the subquery

BWrong comparison operator used

CSubquery returns multiple rows causing error

DIncorrect table name used

Step-by-Step Solution

Solution:

Step 1: Check subquery syntax
The subquery must be enclosed in parentheses to be valid in the WHERE clause.
Step 2: Identify the missing parentheses
The query misses parentheses around SELECT id FROM departments WHERE name = 'Sales', causing syntax error.
Final Answer:
Missing parentheses around the subquery -> Option A
Quick Check:
Subqueries need parentheses to be valid [OK]

Quick Trick: Always put subqueries inside parentheses [OK]

Common Mistakes:

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Identify the error in this query: