Question

假设我们有下表

_________________________________________________________________________
|FlightNo | DepartureDate       | Origin  | Destination | Flightduration |
_________________________________________________________________________
| IB233   | 2018-12-31 09:30:45 | Berlin   | Barcelona  | 200            |
| IB222   | 2019-01-01 12:20:34 | Barcelona| Rome       | 100            |
| LE111   | 2019-01-01 11:11:11 | Rome     | NY         | 400            |
__________________________________________________________________________

现在，我想计算纽约目的地和柏林开始之间的时差。 我要检查整个飞行时间是否小于660分钟。

我已经解决了，但是没用..

SELECT 
  TIMEDIFF(
    (SELECT adddate(DepartureDate, INTERVAL FlightDuration  
MINUTE) 
     FROM flightexecution 
     where ICAO_Code_Origin = 'Berlin'), 
    (SELECT DepartureDate 
     FROM flightexecution 
     where ICAO_Code_Destination = 'NY' AND ICAO_Origin NOT LIKE 'Berlin' AND)
) from flightexecution ;

MySQL的结果只是给我一个“ OK”，这意味着有些错误...

你们能帮我吗？

Answer 1

您可以尝试像这样的自联接查询

SELECT
    A.Origin,
    (TIME_TO_SEC(TIME_DIFF(A.DepartureDate, C.DepartureDate))/60 - A.FlightDuration - B.FlightDuration) AS `Transfer time (minutes)`,
    A.DepartureDate,
    (TIME_TO_SEC(TIME_DIFF(A.DepartureDate, C.DepartureDate))/60 + C.FlightDuration) AS `Overall Duration (minutes)`
FROM
    flightexecution A INNER JOIN
    flightexecution B 
        ON A.Destination = B.Origin INNER JOIN
    flightexecution C 
        ON B.Destination = C.Origin 
WHERE
    A.Origin = 'Berlin'
    AND C.Destination = 'NY'

MYSQL：棘手的查询-需要建立中间变量吗？

1 个答案: