Code First Relationships - entity-framework

Question

I'm having some unexpected results when using code first and I know it has to do with how EF is creating relationships but I can't figure it out. Here is what I have.
Product class, KitComponent class (hold a product, and a qty, etc)
A Product has many KitComponents
A KitComponent has many Products
End result is to show a product, and this product has some other products included as a kit. It may contain 1 of a product or 2 pieces, thats why I need a KitComponent class / table, to hold the other info.
For the longest time I struggled with the ef relationships. The database would put the ParentProductId and Parent Product into the IncludedProductID and IncludedProduct. NOW i fixed that but don't know how but the IncludedProduct field is not being populated. The IncludedProductID is now correct in database. What Am I missing so that when I pull a product and cycle through the kitCOmponents that the IncludedProduct is not null.
AND on top of that, have I correctly described the relationships in the config?
Product:
public class Product
{
public Product()
{
this.KitComponents = new HashSet<KitComponent>();
}
public int Id { get; set; }
public string PartNumber { get; set; }
public virtual ICollection<KitComponent> KitComponents { get; set; }
}
KitComponent:
public class KitComponent
{
public int Id { get; set; }
public string UOM { get; set; }
public int QTY { get; set; }
public int ParentProductId { get; set; }
public Product ParentProduct { get; set; }
public int IncludedProductId { get; set; }
public Product IncludedProduct { get; set; }
}
DBContext With fluent API code:
public class ProductContext : DbContext
{
public DbSet<Product> Products { get; set; }
public DbSet<KitComponent> KitComponents { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<Product>().HasMany(p => p.KitComponents)
.WithRequired(k => k.ParentProduct)
.HasForeignKey(p => p.ParentProductId);
modelBuilder.Entity<KitComponent>().HasRequired(k => k.IncludedProduct)
.WithMany()
.HasForeignKey(k => k.IncludedProductId)
.WillCascadeOnDelete(false);
}
}
Simple Seed Method to Demo Data:
public class ProductContextInitializer : DropCreateDatabaseAlways<ProductContext>
{
private ProductContext db = new ProductContext();
protected override void Seed(ProductContext context)
{
Product prod1 = new Product { PartNumber = "P1" };
Product prod2 = new Product { PartNumber = "P2" };
Product prod3 = new Product { PartNumber = "P3" };
Product prod4 = new Product { PartNumber = "P4" };
Product prod5 = new Product { PartNumber = "P5" };
Product prod6 = new Product { PartNumber = "P6" };
Product prod7 = new Product { PartNumber = "P7" };
db.Products.Add(prod1);
db.Products.Add(prod2);
db.Products.Add(prod3);
db.Products.Add(prod4);
db.Products.Add(prod5);
//db.Products.Add(prod6);
//db.Products.Add(prod7);
db.SaveChanges();
var kitComp = new KitComponent() { IncludedProduct = prod2, QTY = 1, UOM = "EA" };
prod1.KitComponents.Add(kitComp);
db.SaveChanges();
}
}

Answer 1

In order for the property to load, you have to make the navigation property virtual:
public virtual Product IncludedProduct { get; set; }
All the code first conventions can be found here: https://msdn.microsoft.com/en-us/data/jj679962.aspx