Entity Framework ApplicationUser child entities return null

Question

We have an ApplicationUser class which inherits from IdentityUser. An ApplicationUser can have many devices.

    public class ApplicationUser : IdentityUser
{
    public virtual ICollection<Device> Devices { get; set; }
}

A Device is defined as

    public partial class Device
{
    [Key]
    public int DeviceID { get; set; }
    public string UserId { get; set; }
    public virtual ApplicationUser User { get; set; }
    public string DeviceName { get; set; }
}

The one-to-many relationship is set in

protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        base.OnModelCreating(modelBuilder);

            modelBuilder.Entity<Device>(entity =>
        {
            entity.HasKey(e => e.DeviceID);

            entity.Property(e => e.DeviceName)
                .IsRequired()
                .HasMaxLength(50)
                .HasColumnType("varchar");

            entity.Property(e => e.UserId)
                .IsRequired()
                .HasMaxLength(450);

            entity.HasOne(d => d.User).WithMany(p => p.Devices).HasForeignKey(d => d.UserId).OnDelete(DeleteBehavior.Restrict);
        });

        public virtual DbSet<Device> Devices { get; set; }
}

The following code correctly returns the user

var membershipUser = await _userManager.FindByEmailAsync(email);

I know membershipUser has 6 devices in the Devices table, however the Devices property is null.

The following also returns null for this users devices

var deviceList = membershipUser.Devices.ToList();

How do I wire up Devices so they are correctly returned?

Answer 1

Lazy loading doesn't work on EF7. But You can use Include in your request.