595. Big Countries

Problem Statement

Table: World

Column Name	Type
name	varchar
continent	varchar
area	int
population	int
gdp	big int

name is the primary key (column with unique values) for this table.

Each row of this table gives information about the name of a country, the continent to which it belongs, its area, the population, and its GDP value.

A country is big if it has an area of bigger than $3,000,000k{m}^2$ or a population of more than $25,000,000$.

Instructions

• Write a solution to find the name, population, and area of the big countries.
• Return the result table in any order.
• The result form is the following example.

Example

Input: World table

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

Submissions

PostgreSQL

SELECT name, population, area
FROM World
WHERE area >= 3000000 OR population >= 25000000

Pandas

import pandas as pd

def big_countries(world: pd.DataFrame) -> pd.DataFrame:
    return world.loc[(world['area'] >= 3000000) | (world['population'] >= 25000000), ['name', 'population', 'area']]

Explanations

PostgreSQL

Submitted by @noeyislearning

• SELECT name, population, area: This part of the statement specifies the columns that you want to retrieve from the database. In this case, you're retrieving the name, population, and area columns.
• FROM World: This part of the statement specifies the table from which you want to retrieve the data. In this case, you're retrieving data from the World table.
• WHERE area >= 3000000 OR population >= 25000000: This is the condition for selecting the rows. Only rows that satisfy this condition will be included in the result. The condition here is that either the area should be greater than or equal to 3,000,000 or the population should be greater than or equal to 25,000,000. The OR operator ensures that if either of these conditions is met, the row will be included in the result.

Pandas

Submitted by @noeyislearning