[Solved] Identify the error in this query that tries to calculate a cumulative sum of sales per region:SELECT region, sales, SUM(sales) OVER (PARTITION region ORDER BY date) AS running_total FROM sales_data; | PostgreSQL

PostgreSQL - Window Functions in PostgreSQL

Identify the error in this query that tries to calculate a cumulative sum of sales per region:

SELECT region, sales, SUM(sales) OVER (PARTITION region ORDER BY date) AS running_total FROM sales_data;

ASUM() cannot be used as a window function.

BMissing parentheses around PARTITION BY clause.

CORDER BY cannot be used inside OVER().

DPARTITION keyword should be PARTITION BY.

Step-by-Step Solution

Solution:

Step 1: Check window function syntax
The correct syntax requires PARTITION BY, not just PARTITION.
Step 2: Validate other parts
ORDER BY inside OVER() is valid for running totals, and SUM() is allowed as a window function.
Final Answer:
PARTITION keyword should be PARTITION BY. -> Option D
Quick Check:
Use PARTITION BY, not PARTITION alone [OK]

Quick Trick: Use PARTITION BY, not just PARTITION [OK]

Common Mistakes:

Master "Window Functions in PostgreSQL" in PostgreSQL

9 interactive learning modes - each teaches the same concept differently

Identify the error in this query that tries to calculate a cumulative sum of sales per region: