mysql - 实现满足两个条件的Mysql子查询

如果两个条件正确，即是否有flightno，我需要获取flightno with airportcode ='something' AND if there is a flightno with airportcode='another'。
如果两个航班号都相同，则返回航班号。

我试过了

select flightno
from airport
where flightno = (
  select flightno from airport
  where airport_code='blr')
  AND
  (select flightno from airport where airport_code='goy')
  )

最佳答案

您的尝试已接近。尝试这个：
select flightnofrom airportwhere flightno IN (select flightno from airport where airport_code='blr') AND flightno IN (select flightno from airport where airport_code='goy')
并以更有效的方式：
select flightnofrom airport as awhere exists ( select 1 from airport as b where a.flightno = b.flightno and airport_code='blr' )and exists ( select 1 from airport as c where a.flightno = c.flightno and airport_code='goy' )