Entity Framework: The 'ComplexType.Field' property does not exist or is not mapped to type 'Entity'

Question

I have a problem with mapping properties on value objects/complex types to entities. I have a user entity which has a complex type property called Credential, which in turn has properties: Email, UserName, Password and SecurityStamp. I am trying to map properties from complex type to entities, and the source code is shown below:

public class User
{
    public string Id { get; protected set; }
    public Credential Credential { get; protected set; }
    // unrelated properties and methods omitted for simplicity
}

public sealed class Credential: ValueObject<Credential>
{
    public string Email { get; private set; }
    public string UserName { get; private set; }
    public string Password { get; private set; }
    public string SecurityStamp { get; private set; }

    public Credential() { }

    public Credential(string email, string userName, string password, string securityStamp)
    {
        Email = email;
        UserName = userName;
        Password = password;
        SecurityStamp = securityStamp;
    } 

public class CoreContext: DbContext
{
    public IDbSet<User> Users { get; set; }

    public CoreContext(string connectionString) : base(connectionString) {}

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        Database.SetInitializer<CoreContext>(null);

        modelBuilder.ComplexType<Credential>().Property(ucr => ucr.Email).HasColumnName("Email");
        modelBuilder.ComplexType<Credential>().Property(ucr => ucr.UserName).HasColumnName("UserName");
        modelBuilder.ComplexType<Credential>().Property(ucr => ucr.Password).HasColumnName("Password");
        modelBuilder.ComplexType<Credential>().Property(ucr => ucr.SecurityStamp).HasColumnName("SecurityStamp");

        modelBuilder.Entity<User>().Property(u => u.Credential.Email).HasColumnName("Email");
        modelBuilder.Entity<User>().Property(u => u.Credential.UserName).HasColumnName("UserName");
        modelBuilder.Entity<User>().Property(u => u.Credential.Password).HasColumnName("Password");
        modelBuilder.Entity<User>().Property(u => u.Credential.SecurityStamp).HasColumnName("SecurityStamp");
    }
}

As you see, I was trying to map complex type properties to the entity. I started by configuring Credential as a complex type, and then configure the properties on entity User. However, I am receiving the following error:

The 'Credential.Email' property does not exist or is not mapped for the type 'User'.

I dont understand why this happens. I've done everything I can to configure complex type mapping, why it wont work? Anyone have ideas on what I may have done wrong?

Answer 1

Not been able to reproduce this:

I've got this after add-migration with the same setup you have:

public override void Up()
{
    CreateTable(
            "dbo.Users",
            c => new
            {
                Id = c.String(nullable: false, maxLength: 128),
                Email = c.String(),
                UserName = c.String(),
                Password = c.String(),
                SecurityStamp = c.String()
            })
        .PrimaryKey(t => t.Id);
}

The only thing I've removed is your base class on Credential: ValueObject because I don't have it. Everything looks good so maybe there's something wrong with that class?