MySQL:需要有关 MySQL 逻辑的帮助

Question

我正在尝试解决一个 MySQL 问题，我几乎已经解决了... 问题是……

要获取墨西哥人口超过 500,000 的所有城市，您会运行什么查询？按人口降序排列结果。

这是我正在处理的表格...

我当前的代码...

SELECT cities.name, cities.population
FROM countries
LEFT JOIN cities
ON countries.id = cities.country_id
WHERE cities.population < 500000

我觉得我应该 super 亲密。有什么指点吗？

Answer 1

想通了。我所需要的只是多一点细节!

旧代码...

SELECT cities.name, cities.population
FROM countries
LEFT JOIN cities
ON countries.id = cities.country_id
WHERE cities.population < 500000

新代码...

SELECT cities.name, cities.population
FROM countries 
LEFT JOIN cities
ON countries.id = cities.country_id
WHERE countries.name = 'Mexico' AND cities.population < 500000
GROUP BY cities.name
ORDER BY cities.name DESC