How adding items to list

I have model in my project. Here is code of model

public partial class Logging
{
    public string Imei { get; set; }
    public DateTime CurDateTime { get; set; }
    public Nullable<System.DateTime> GPSDateTime2 { get; set; }
    public Nullable<decimal> Latitude2 { get; set; }
    public Nullable<decimal> Longitude2 { get; set; }
    public string Speed { get; set; }
    public Nullable<int> Datatype { get; set; }
    public int Id { get; set; }
    [NotMapped]
    public TimeSpan? FirstStartDifference
    {
        get
        {
            if (CurDateTime != null)
            {
                var midnight = new DateTime(CurDateTime.Year, CurDateTime.Month, CurDateTime.Day, 00, 00, 00);
                var difference = CurDateTime - midnight;
                return difference;
            }
            return null;
        }
    }
    [NotMapped]
    public TimeSpan? LastStartDifference
    {
        get
        {
            if (CurDateTime != null)
            {
                var midnight = new DateTime(CurDateTime.Year, CurDateTime.Month, CurDateTime.Day, 23, 59, 00);
                var difference = midnight - CurDateTime;
                return difference;
            }
            return null;
        }
    }
    [NotMapped]
    public int coeff = 2;
}

I need to get some items from database , it’s first entry, where Datatype==1 and Last where Datatype ==2.

So I write this method on back-end

public JsonResult GetStops()
{
    using (var ctx = new GoogleMapTutorialEntities())
    {      
        var firstitem = ctx.Loggings.Where(x => x.Datatype == 2).AsEnumerable().Select(
               x => new
               {
                   lng = x.Longitude2,
                   lat = x.Latitude2,
                   difference = (int)(x.FirstStartDifference?.TotalMinutes ?? -1) * x.coeff
               }).FirstOrDefault();
        var lastItem = ctx.Loggings.Where(x => x.Datatype == 2).AsEnumerable().Select(
               x => new
               {
                   lng = x.Longitude2,
                   lat = x.Latitude2,
                   difference = (int)(x.LastStartDifference?.TotalMinutes ?? -1) * x.coeff
               }).LastOrDefault();
        List<Logging> items = new List<Logging> {firstitem, lastItem};
        return Json(firstitem, JsonRequestBehavior.AllowGet);
    }
}

After this I need to add firstitem and lastitem to list.

I write it like this List<Logging> items = new List<Logging> {firstitem, lastItem};

But I get an error

Severity Code Description Project File Line Suppression State
Error CS1950 The best overloaded Add method ‘List.Add(Logging)’ for the collection initializer has some invalid arguments Heatmap C:UsersnemessourcereposHeatmapHeatmapControllersHomeController.cs 37 Active
Severity Code Description Project File Line Suppression State
Error CS1503 Argument 1: cannot convert from ” to ‘Heatmap.Models.Logging’ Heatmap C:UsersnemessourcereposHeatmapHeatmapControllersHomeController.cs 37 Active

for this List<Logging> items = new List<Logging> {firstitem, lastItem};

How I can add them to List?

Answers:

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Method 1

You are returning an anonymous type instead of Logging. The firstitem and lastItem are Anonymous Types. Change your code to this:

x => new Logging
{
    Longitude2 = x.Longitude2,
    Latitude2 = x.Latitude2,
    //And other properties
}

And if you still get error probably it is because you cannot project onto a mapped entity then you need to create a DTO class with needed properties from the Logging entity:

public class LoggingDTO
{
    public string Longitude2 { get; set; }
    public string Latitude2  { get; set; }
    //And other properties
}

Then:

x => new LoggingDTO

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