[Solved] Given the table sales with columns region and amount, what will this query return?SELECT region, SUM(amount) FILTER (WHERE amount > 100) AS big_sales FROM sales GROUP BY region; | PostgreSQL

PostgreSQL - Aggregate Functions and GROUP BY

Given the table sales with columns region and amount, what will this query return?

SELECT region, SUM(amount) FILTER (WHERE amount > 100) AS big_sales FROM sales GROUP BY region;

ASum of all sales amounts per region.

BCount of sales with amount greater than 100 per region.

CSum of sales amounts less than or equal to 100 per region.

DSum of sales amounts greater than 100 per region.

Step-by-Step Solution

Solution:

Step 1: Understand the FILTER condition in SUM
The FILTER clause limits the SUM to only rows where amount > 100.
Step 2: Analyze the GROUP BY effect
The query groups rows by region, then sums only amounts above 100 in each group.
Final Answer:
Sum of sales amounts greater than 100 per region. -> Option D
Quick Check:
SUM with FILTER (WHERE amount > 100) = sum of big sales [OK]

Quick Trick: FILTER limits rows inside SUM to amount > 100 [OK]

Common Mistakes:

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Given the table sales with columns region and amount, what will this query return?