mysql - SQL:获取 parent Join child where child type = 1 AND child type = 2

Question

我对 SQL(MySQL 环境)有疑问。我有两个表:

Airports
--------------------
id    type   city_id
1     2      1
2     3      1
3     4      2


City
----------
id    name
1     Paris
2     Lyon

我想要机场类型为 2 和 3 的城市。

我试过了:

SELECT *
FROM city c INNER JOIN airports a ON a.city_id = c.id
WHERE a.type = 1 AND a.type = 2

但它不起作用。

有什么想法吗？

Answer 1

如果您需要同时存在 1 类和 2 类机场的城市，请尝试使用此查询:

SELECT * FROM CITY
JOIN
  (
     SELECT CITY_ID FROM Airports WHERE type in (1,2)
     GROUP BY CITY_ID
     HAVING COUNT(DISTINCT type) =2
   ) as A
  ON City.ID=a.City_id