[SQL] 595. Big Countries (Easy)

다음은 or 조건을 사용하는 문제이다

https://leetcode.com/problems/big-countries/description/?envType=study-plan-v2&envId=top-sql-50

⬆️ 문제 전문 링크

 

Table: World

+-------------+---------+
| Column Name | Type    |
+-------------+---------+
| name        | varchar |
| continent   | varchar |
| area        | int     |
| population  | int     |
| gdp         | bigint  |
+-------------+---------+
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 at least three million (i.e., 3000000 km2), or
it has a population of at least twenty-five million (i.e., 25000000).
Write a solution to find the name, population, and area of the big countries.

Return the result table in any order.

The result format is in the following example.

 

Example 1:

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 |
+-------------+------------+---------+

 

World 테이블에서 다음 조건을 만족하는 나라의 이름, 인구, 면적을 뽑는 문제이다.

<조건>

* 인구(population) >= 25,000,000

* 면적(area) >= 3,000,000

 

조건 둘중에 하나라도 만족하면 추출 대상임으로 or 조건을 where 조건절에 사용해준다.

 

정답 쿼리는 다음과 같다.

select name, population, area
from World
where area >= 3000000
or population >= 25000000;