Big Countries

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Medium

Description

You are given a World table containing information about countries. A country is considered big if: - it has an area of at least 3,000,000 km², OR - it has a population of at least 25,000,000. Write a SQL query to find the name, population, and area of all big countries. Return the result in any order.

Database Schema

World

Column Name	Example Value
name	Afghanistan
continent	Asia
area	652230
population	25500100
gdp	20343000000

Example

World

name	continent	area	population	gdp
Afghanistan	Asia	652230	25500100	20343000000
Albania	Europe	28748	2831741	12960000000
Algeria	Africa	2381741	37100000	188681000000
Andorra	Europe	468	78115	3712000000
Angola	Africa	1246700	20609294	100990000000

Output

name	population	area
Afghanistan	25500100	652230
Algeria	37100000	2381741

Explanation:

Afghanistan qualifies because its population (25500100) >= 25000000. Algeria qualifies because its population (37100000) >= 25000000. Albania, Andorra, and Angola do not meet either condition.

Approach hint

Start with a simple approach, explain the trade-off, then move toward a cleaner or more scalable solution.

Common mistake

Skipping assumptions, edge cases, or trade-offs can make an otherwise good answer feel incomplete.