595. 大的国家

# Write your MySQL query statement below
SELECT name, population, area
FROM World
WHERE population>25000000 OR area>3000000

这里有张 World 表

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

如果一个国家的面积超过300万平方公里,或者人口超过2500万,那么这个国家就是大国家。

编写一个SQL查询,输出表中所有大国家的名称、人口和面积。

例如,根据上表,我们应该输出:

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

方法1:multiple WHERE clauses实现

# Write your MySQL query statement below
SELECT name, population, area
FROM World
WHERE population>25000000 OR area>3000000

方法2:UNION实现

# Write your MySQL query statement below
SELECT name, population, area
FROM World
WHERE population>25000000 
UNION
SELECT name, population, area
FROM World
WHERE area>3000000

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转载自blog.csdn.net/Scarlett_Guan/article/details/82942964
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