[Solved] Identify the error in this query:SELECT employee_id, salary, COUNT(*) OVER PARTITION BY department FROM employees; | PostgreSQL

PostgreSQL - Window Functions in PostgreSQL

Identify the error in this query:

SELECT employee_id, salary, COUNT(*) OVER PARTITION BY department FROM employees;

ACOUNT(*) cannot be used as a window function.

BMissing parentheses around PARTITION BY clause in OVER().

Cemployee_id cannot be selected with window functions.

DNo error; query is correct.

Step-by-Step Solution

Solution:

Step 1: Check syntax of window function
OVER clause must have parentheses: OVER (PARTITION BY department).
Step 2: Validate other parts
COUNT(*) is valid as window function; selecting employee_id is allowed.
Final Answer:
Missing parentheses around PARTITION BY clause in OVER(). -> Option B
Quick Check:
OVER() requires parentheses [OK]

Quick Trick: Always use parentheses after OVER keyword [OK]

Common Mistakes:

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Identify the error in this query: