Question

I use the code below to get records from two tables but I want to have the result in a List. I used the code below, but this error occured:

Cannot implicitly convert type
System.Collections.Generic.List<AnonymousType#1> to
System.Collections.Generic.List<QuickRoutes.DAL.Route>

public List<Route> GetAllForUser(Guid userId)
{
    // var result = new List<Route>();
    aspnetdbDataContext aspdb = new aspnetdbDataContext();
    List<Route> result  = (from r in aspdb.Routes
                where r.UserId == userId
                join t in aspdb.TrackPoints on r.RouteId equals t.RouteFK
                select t.TrackPointId,t.RouteFK,t.TrackTime,t.Longitude,t.Latitude,t.Elevation, r.SourceName).ToList();
    return result;
}

EDIT:

I want to match my query with this class:

namespace QuickRoutes.Entities
{
    public enum RouteType
    {
        Route, Waypoints, Track
    }

    public sealed class Route
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public DateTime Time { get; set; }
        public List<TrackPoint> TrackPoints { get; set; }
        public Guid UserId { get; set; }
        public string GpxData { get; set; }
        public RouteType RouteType { get; set; }


        public Route(int id)
        {
            Id = id;
            TrackPoints = new List<TrackPoint>();
        }
......

but if I change my code to this one,It doesn’t work too

List<Route> result = (from r in aspdb.RouteLinqs
                                  where r.UserId == userId
                                  join t in aspdb.TrackPointlinqs on r.RouteId equals t.RouteFK
                                  select r).ToList();

to be honest I want to change this function that is written with SQL to LINQ,have any better idee?

namespace QuickRoutes.Entities
{
    public enum RouteType
    {
        Route, Waypoints, Track
    }

    public sealed class Route
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public DateTime Time { get; set; }
        public List<TrackPoint> TrackPoints { get; set; }
        public Guid UserId { get; set; }
        public string GpxData { get; set; }
        public RouteType RouteType { get; set; }


        public Route(int id)
        {
            Id = id;
            TrackPoints = new List<TrackPoint>();
        }
......

Answer 1

It’s because your projection (what you’re selecting) isn’t the same as a Route (what you’re trying to return);

If you wish to return a Route Change your select to:

select r

If you wish to return your joined projection, you’l have to create a new type, and return that:

e.g:

public class RouteTrack
{
    public TrackPointId ...
    public RouteFK ...
    public TrackTime ...
}

And return a List<RouteTrack> from your method, and change your select to:

select new RouteTrack { TrackPointId = t.TrackPointId .... }