retrieve 5 last records from table by C#

Question

I want to retrieve 5 last record of one of my tables in Data base by C# code.I don't want using query in Sql server. in my code I want to retrieve 5 last records in tt.what do I do? now it retrieves all of the Records

            var temp = db.Positions.Where(P => P.DeviceID == device.ID);
            List<Position> tempPositions = FilterPosition(temp.ToList<Position>());
            var tt = FilterStops(tempPositions, new TimeSpan(0, 30, 0), 100);
            List<JsonDevicePositionModel> returnPositions = (

                                          from p in tt

                                             select new 
                                                 JsonDevicePositionModel

                                             {
                                                 DeviceID = p.Position.DeviceID,
                                                 Latitude = p.Position.Latitude,
                                                 Longitude = p.Position.Longitude,
                                                 SerialNumber = p.Position.Device.SerialNumber,

                                                 Speed = p.Position.Speed,


                                             }).ToList(); 

            //    }
            return Json(returnPositions, JsonRequestBehavior.AllowGet);

        }

Answer 1

如果您不必担心性能，则可以使用扩展方法Take of Enumerable类：

var tt = FilterStops(tempPositions, new TimeSpan(0, 30, 0), 100).Take(5);

Answer 2

你可以试试 ...

from p in tt.GetRange(tt.Count - 6, 5)

Answer 3

另一种可能性：来自tt.Skyp（tt.Count-5）中的p.Take（5）

Answer 4

var full = FilterStops(tempPositions, new TimeSpan(0, 30, 0), 100);
var tt= full.Skip(full.Count - 5);