Question

I am making an MCV open-hours admin, in which I have a class Schedule containing an ICollection of ExceptionHoursSets, each HoursSet further containing a WeekSpec. (The ExceptionHoursSets contain hours which define exceptions to a general WeekSpec hours pattern also contained in Schedule.)

Schedule.cs (abbreviated):

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;

namespace HoursAdmin.Models
{
    public class Schedule
    {
        [Required]
        public Guid ScheduleId { get; set; }

        // Miscellaneous props

        // General hours pattern
        public Guid WeekSpecId { get; set; }
        public virtual WeekSpec WeekSpec { get; set; }

        // All exceptions to that pattern
        virtual public ICollection<ExceptionHoursSet> ExceptionHoursSets { get; set; }
    }
}

ExceptionHoursSet.cs (also abbreviated):

using System;
using System.ComponentModel.DataAnnotations;

namespace HoursAdmin.Models
{
    public class ExceptionHoursSet
    {
        [Required]
        public Guid ExceptionHoursSetId { get; set; }

        // More misc props

        public Guid WeekSpecId { get; set; }
        [Required]
        public WeekSpec WeekSpec { get; set; }
    }
}

WeekSpec.cs (abbreviated still):

using System;
using System.ComponentModel.DataAnnotations;

namespace HoursAdmin.Models
{
    public class DaySpec
    {
        [Required]
        public Guid DaySpecId { get; set; }

        // Good old misc props
    }
}

If I retrieve the Schedule, the HoursSet collection loads, but each HoursSet’s WeekSpec is null. I am currently disposed to ignore the nagging sense that I should use only Code First loading, and manually query for the WeekSpec whose ID matches that stored as the ExceptionHoursSet’s foreign key:

public ViewResult Index()
{
    using (var db = new HoursDb())
    {
        var schedules = db.Schedules.ToList();
        foreach (var schedule in schedules)
        {
            var exceptionHoursSets = schedule.ExceptionHoursSets;
            foreach (var exceptionHoursSet in exceptionHoursSets)
            {
                var weekSpec = db.WeekSpecs.FirstOrDefault(d => d.WeekSpecId == 
                    exceptionHoursSet.WeekSpecId);
                exceptionHoursSet.WeekSpec = weekSpec;
                db.Entry(weekSpec).Collection(w => w.DaySpecs).Load();
            }
        }
        return View(schedules);
    }
}

However, this is repetitive and tedious… so would anyone mind furnishing how this should be done?

P.S. — The answer supplied in Auto-retrieve ICollection of complex type with Code First won’t work, because as you can see I cannot put a nav prop in the WeekSpec to its parent entity, since that entity may either be a Schedule or an ExceptionHoursSet (see How to define an MVC database structure using the same sub-table in different super-tables).

Much appreciated,
Nathan Bond

Answer 1

 var schedules = db.Schedules
    .Include(s => s.WeekSpec)
    .Include(s => s.ExceptionHoursSets)
    .Include(s => s.ExceptionHoursSets.Select(e => e.WeekSpec))
    .ToList();