Question

我正在尝试添加此查询中的结果数。 UCASE(RIGHT(DepartureTime,2))给我四个PM，一个AM给五个。我希望它只是一个AM柱和一个PM柱，EX：AM | 1，ABOVE PM | 4。

我目前收到错误

您的查询不包含指定的表达式“UCASE(RIGHT(DepartureTime,2))”作为聚合函数的一部分

SELECT UCASE(RIGHT(DepartureTime,2)) AS [Time of Departure], COUNT(*) AS [PassengerCount]
FROM Flight
WHERE FlightNumber IN


  (SELECT FlightNumber
   FROM Manifest
   WHERE FlightDate BETWEEN #07/01/2016# AND #12/31/2016# AND PassengerNumber IN


      (SELECT PassengerNumber
       FROM Passenger
       WHERE FFNumber IN

        (SELECT FFNumber
         FROM FrequentFlyer
         WHERE PremierStatus = 3)));

Answer 1

您收到错误是因为您在查询中引入了一个聚合函数，而没有在最后附加guard let currentViewController = self.VCArr.first else { return }子句。

通过添加GROUP BY修改您的查询。 GROUP BY DepartureTime子句将您的记录分组为摘要。

下面的代码应该会给你预期的结果，但我还没试过。

GROUP BY

问题计数导致嵌套查询

1 个答案: