Linq Group by获取数据的总和和计数c＃

Question

我有一个包含四个字段的数据集（DriverNo，Airport，SumAmount和count） 机场可以很多，sumAmount是机场旅行产生的司机数量 我想找出每个司机去机场的行程和他赚了多少。

所以我检索的数据应该很有趣

我的linq就像是跟随我，但我怀疑结果

var list = db.Booking1
  .Where(w => w.Gen_Location.LocationTypeId == 
                Enums.LOCATION_TYPES.AIRPORT)
  .Select(w => new
     {
       DriverNo = w.Fleet_Driver.DriverNo,
       Airport = w.Gen_Location.LocationName,
       Amount = w.CustomerPrice,
       driverId = w.DriverId
     })
  .GroupBy(w => w.Airport)
  .Select(w => new
     {
       DriverNo = w.First().DriverNo,
       Airport = w.First().Airport,
       SumAmount = w.Sum(a => a.Amount),
       driverId = w.First().driverId,
       count = w.Count()
     })
  .ToList();

任何帮助将不胜感激

Answer 1

  

我想找出每个司机去机场的行程和他赚了多少。

如果是这种情况，那么您还需要按驾驶员分组，现在是您在机场的唯一分组。然后，您可以使用密钥获取所需的数据

var list = db.Booking1
  .Where(w => w.Gen_Location.LocationTypeId == 
            Enums.LOCATION_TYPES.AIRPORT)
   .Select(w => new
     {
       DriverNo = w.Fleet_Driver.DriverNo,
       Airport = w.Gen_Location.LocationName,
       Amount = w.CustomerPrice,
       driverId = w.DriverId
     })
  .GroupBy(w => new { w.Airport, w.DriverId})
  .Select(w => new
     {
       // You can put this in the key too but in this case
       // I'll grab it from the first element
       DriverNo = w.First().DriverNo,
       //It's more clear to get this from the key
       Airport = w.Key.Airport,
       SumAmount = w.Sum(a => a.Amount),
       //It's more clear to get this from the key
       driverId = w.Key.driverId,
       count = w.Count()
     })
  .ToList();

说实话，所有这些都应该放在自己的类中。如果您需要过滤特定驱动程序的数据，例如4。

list.Where(x => x.driverId == 4);