public IQueryable GetRentsFullDetails()
 {
     db.Database.Log = s => System.Diagnostics.Debug.WriteLine(s);
     return(GetRentDetails().GroupJoin(db.spGetCars(), rent => rent.CarID, car => car.ID,
                                       (rent, car) => new { rent, car }).SelectMany(z => z.car.DefaultIfEmpty(),
                                                                                    (r, c) => new
     {
         r.rent.ID,
         r.rent.StartDate,
         r.rent.EndDate,
         r.rent.ActualEndDate,
         r.rent.UserID,
         Image = c == null ? null : c.Image
     })
            .GroupJoin(db.spGetUsers(), r => r.UserID, u => u.ID, (r, u) => new { r, u })
            .SelectMany(s => s.u.DefaultIfEmpty(), (r, u) =>
                        new
     {
         r.r.ID,
         r.r.StartDate,
         r.r.EndDate,
         r.r.ActualEndDate,
         r.r.Image,
         UserName = u == null ? null : u.UserName,
         LastName = u == null ? null : u.LastName,
         FirstName = u == null ? null : u.FirstName
     }));
 }
 // GET: api/Cars
 public IQueryable <spGetCars_Result> GetCars()
 {
     return(db.spGetCars().AsQueryable());
 }