EF Migration is generating a second index for the aggregate PK - sql-server

Question

I am trying to create a new migration for my project and i just depared with an awkward situation... I have my aggregate root entity:
public class Classroom : Entity, IAggregateRoot
{
// PK
public int ClassroomId { get; set; }
// ....
public virtual ClassroomStreaming Streaming { get; set; }
}
And the aggregate:
public class ClassroomStreaming : Entity
{
// PK
public int ClassroomId { get; set; }
public virtual Classroom Classroom { get; set; }
// Fields
public string EmbedCode { get; set; }
// ...
}
The mappings are:
public class ClassroomMap : EntityTypeConfiguration<Classroom>
{
public ClassroomMap()
{
this.HasKey(t => t.ClassroomId);
this.ToTable("Classroom");
// ....
// One to One
this.HasOptional(t => t.Streaming)
.WithRequired(p => p.Classroom);
}
}
and:
public class ClassroomStreamingMap: EntityTypeConfiguration<ClassroomStreaming>
{
public ClassroomStreamingMap()
{
// Primary Key
this.HasKey(t => new { t.ClassroomId });
// Table & Column Mappings
this.ToTable("ClassroomStreaming");
this.Property(t => t.ClassroomId)
.HasDatabaseGeneratedOption(DatabaseGeneratedOption.None);
// Relationships
this.HasRequired(t => t.Classroom)
.WithOptional(p => p.Streaming)
.WillCascadeOnDelete(true);
}
}
When I generate the migration, i get the following situation where it creates the PK and also an non clustered index for the same column:
public override void Up()
{
CreateTable(
"dbo.ClassroomStreaming",
c => new
{
ClassroomId = c.Int(nullable: false),
// ....
})
.PrimaryKey(t => t.ClassroomId)
.ForeignKey("dbo.Classroom", t => t.ClassroomId, cascadeDelete: true)
.Index(t => t.ClassroomId);
}
Is it a normal behavior? look how it is in the SQL Server:

Answer 1

It looks like based you have "double-mapped" your relationships in the two EntityTypeConfiguration<T> classes. I think you only need to define the relationship in one direction.
The Entity Framework Fluent API documentation states that for one-to-zero-or-one relationships, define it with .HasOptional().WithRequired() as you have done in the ClassroomMap. You should be able remove the .HasRequired().WithOptional() in the ClassroomStreamingMap class.