Entity Framework Creates unwanted relationship between abstract and derived tables

Question

Using code first, I have some abstract classes and some classes derived from those abstracted classes.

// Abstracted Classes
public abstract class Brand
{
  [Key]
  public int Id { get; set; }
  public string Name { get; set; }
}

public abstract class Model
{
  [Key]
  public int Id { get; set; }
  public string Name { get; set; }

}

// Derived Classes
[Table("ComparisonBrand")]
public class ComparisonBrand : Brand
{
  public ComparisonBrand()
  {
    ComparisonValues = new List<ComparisonValue>();
    Models = new List<ComparisonModel>();
  }

  public virtual ICollection<ComparisonValue> ComparisonValues { get; set; }
  public virtual ICollection<ComparisonModel> Models { get; set; }
}

[Table("ComparisonModel")]
public class ComparisonModel : Model
{
  public int? BrandId { get; set; }
  public int? LogoId { get; set; }

  [ForeignKey("BrandId")]
  public virtual ComparisonBrand ComparisonBrand { get; set; }
  [ForeignKey("LogoId")]
  public virtual ComparisonLogo ComparisonBrand { get; set; }

  public virtual ICollection<ComparisonValue> ComparisonValues { get; set; }
}

My issue is that the migration generates foreign keys for:

• ComparisonModel.Id > Models.Id
• ComparisonModel.BrandId > Brands.Id
• ComparisonModel.BrandId > ComparisonBrand.Id

Since ComparisonBrand.Id is a FK to Brands.BrandId, I get an error when deleting a Brand record. If I delete the ComparisonModel.BrandId > ComparisonBrand.Id relationship, however, the delete works fine.

How can I prevent a relationship from being formed between both the abstracted table and the derived table (Brands and ComparisonBrand)?

Answer 1

You are using the virtual keyword this causes Lazy Loading . You are telling EF to generate Foreign keys for them through this feature. Drop the virtual and you will not create the keys any longer