WillCascadeOnDelete不使用C＃Entity Framework

Question

我不确定删除Job时为什么没有删除FileList。 它仍然是数据库中的孤儿。

使用Entity Framework 6.0.0.0。 代码优先

modelBuilder.Entity<Job>()
    .HasOptional(u => u.FileList)
    .WithMany()
    .HasForeignKey(j => j.FileListGuid)
    .WillCascadeOnDelete(true);

[Table("Job")]
internal class Job : BaseEntity, IDeletable, IFileList
{
    [Key]
    public Guid Guid { get; set; }

    [ForeignKey("FileList")]
    public Guid? FileListGuid { get; set; }

    public virtual FileList FileList { get; set; }
}

[Table("FileList")]
class FileList : BaseEntity
{
    [Key]
    public Guid Guid { get; set; }

    public virtual ICollection<File> Files { get; set; }
}