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2018/12/14

LeetCode Big Countries

本篇為LeetCode上演算法的超簡單問題,Big Countries

題目如下:

There is a table World

+-----------------+------------+------------+--------------+---------------+
| name            | continent  | area       | population   | gdp           |
+-----------------+------------+------------+--------------+---------------+
| Afghanistan     | Asia       | 652230     | 25500100     | 20343000      |
| Albania         | Europe     | 28748      | 2831741      | 12960000      |
| Algeria         | Africa     | 2381741    | 37100000     | 188681000     |
| Andorra         | Europe     | 468        | 78115        | 3712000       |
| Angola          | Africa     | 1246700    | 20609294     | 100990000     |
+-----------------+------------+------------+--------------+---------------+

A country is big if it has an area of bigger than 3 million square km or a population of more than 25 million.

Write a SQL solution to output big countries' name, population and area.

For example, according to the above table, we should output:

+--------------+-------------+--------------+
| name         | population  | area         |
+--------------+-------------+--------------+
| Afghanistan  | 25500100    | 652230       |
| Algeria      | 37100000    | 2381741      |
+--------------+-------------+--------------+

寫一段MySQL的SQL敘述從上面的World資料表中查詢面積大於三百萬平方公里人口數超過兩千五百萬的大國家。

本題是超級初學者問題,就是要會使用基本的SQL語法SELECTWHEREOR

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

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