希望你能幫助我。 我有一個預訂列表,我想在每組TourOperators中獲得前兩排。如何選擇Linq Group中的前N行
這裏的數據樣本:
List<Booking> list = new List<Booking>();
list.Add(new Booking() { BookingNo = "31111111", DepDate = new DateTime(2011, 5, 1), TourOperator = "SPI" });
list.Add(new Booking() { BookingNo = "32222222", DepDate = new DateTime(2011, 5, 2), TourOperator = "SPI" });
list.Add(new Booking() { BookingNo = "33333333", DepDate = new DateTime(2011, 5, 3), TourOperator = "SPI" });
list.Add(new Booking() { BookingNo = "34444444", DepDate = new DateTime(2011, 5, 4), TourOperator = "SPI" });
list.Add(new Booking() { BookingNo = "35555555", DepDate = new DateTime(2011, 5, 5), TourOperator = "SPI" });
list.Add(new Booking() { BookingNo = "36666666", DepDate = new DateTime(2011, 5, 6), TourOperator = "SPI" });
list.Add(new Booking() { BookingNo = "11111111", DepDate = new DateTime(2011, 5, 1), TourOperator = "VIN" });
list.Add(new Booking() { BookingNo = "12222222", DepDate = new DateTime(2011, 5, 2), TourOperator = "VIN" });
list.Add(new Booking() { BookingNo = "13333333", DepDate = new DateTime(2011, 5, 3), TourOperator = "VIN" });
list.Add(new Booking() { BookingNo = "14444444", DepDate = new DateTime(2011, 5, 4), TourOperator = "VIN" });
list.Add(new Booking() { BookingNo = "15555555", DepDate = new DateTime(2011, 5, 5), TourOperator = "VIN" });
list.Add(new Booking() { BookingNo = "16666666", DepDate = new DateTime(2011, 5, 6), TourOperator = "VIN" });
list.Add(new Booking() { BookingNo = "17777777", DepDate = new DateTime(2011, 5, 7), TourOperator = "VIN" });
我有這個LINQ的,但它只是給了我各組中的第一預訂:
List<Booking> yetAnotherList = list.GroupBy(row => row.TourOperator)
.Select(g => g.OrderBy(row => row.DepDate).First()).ToList();
我所期待的數據是什麼像這樣:
31111111,2011-05-01,SPI
32222222,2011-05-02,SPI
11111111,2011-05-01,VIN
12222222,2011-05-02,VIN
謝謝。
這給了我:不能隱式轉換類型「System.Collections.Generic.List> '到'System.Collections.Generic.List ' –
2011-04-24 10:18:15
JensRud,嘗試使用var並在調試中看到什麼類型hasAnotherList。 – 2011-04-24 10:38:19
哇,謝謝Chris,SelectMany和Take的組合就是我所需要的!正如你指出的那樣,結果需要展開。 – 2011-04-24 11:07:24