在實體框架中添加新記錄時不會自動設置外鍵

Question

我是實體框架的新手，我正在嘗試在表中添加一條具有外鍵約束的記錄。 我有兩個類，一個是用戶，另一個是 FileMovement。 Filemovement 將 userId 作為外鍵。 新記錄添加成功，但外鍵值仍為空。 誰能告訴我我在這里做錯了什么是我的代碼。

我的用戶類代碼

    [Key]
    public int User_ID { get; set; }

    [Display(Name = " User Nmae: ")]
    [Required(ErrorMessage = "User Name is required")]
    public string User_Name { get; set; }

    [Display(Name = " Password: ")]
    [DataType(DataType.Password)]
    [Required(ErrorMessage = "Password is required")]
    public string Password { get; set; }

這是我的 fileMovement 類代碼

    [Key]
    public int file_Id { get; set; }

    [ForeignKey("User")]
    public int User_Id_fk { get; set; }

    [Display(Name = " Diary No: ")]
    [Required(ErrorMessage = "Diary No is required")]
    public string Diary_No { get; set; }

    [Display(Name = " Receive Date: ")]
    [Required(ErrorMessage = "Please enter receive date")]
    [DataType(DataType.Date)]
    [DisplayFormat(DataFormatString = "{0:yyyy-MM-dd}", ApplyFormatInEditMode = true)]
    public Nullable<System.DateTime> Receive_Date { get; set; }

    [Display(Name = " Issued Diary No: ")]
    public string Issued_Diary_No { get; set; }

    [Display(Name = " Issue Date: ")]
    [DataType(DataType.Date)]
    [DisplayFormat(DataFormatString = "{0:yyyy-MM-dd}", ApplyFormatInEditMode = true)]
    public Nullable<System.DateTime> Issue_Date { get; set; }

    [Display(Name = " Office Name: ")]
    public string Issued_Office { get; set; }

    [Display(Name = " Subject: ")]
    [Required(ErrorMessage = "Please enter subject")]
    [DataType(DataType.MultilineText)]
    public string Subject { get; set; }

    [Display(Name = " DG(Rectt): ")]
    [DataType(DataType.Date)]
    [DisplayFormat(DataFormatString = "{0:yyyy-MM-dd}", ApplyFormatInEditMode = true)]
    public Nullable<System.DateTime> DG_Rectt { get; set; }

    [Display(Name = " ADG(Rectt): ")]
    [DataType(DataType.Date)]
    [DisplayFormat(DataFormatString = "{0:yyyy-MM-dd}", ApplyFormatInEditMode = true)]
    public Nullable<System.DateTime> ADG_Rectt { get; set; }

    [Display(Name = " DD(Rectt): ")]
    [DataType(DataType.Date)]
    [DisplayFormat(DataFormatString = "{0:yyyy-MM-dd}", ApplyFormatInEditMode = true)]
    public Nullable<System.DateTime> DD_Rectt { get; set; }

    [Display(Name = " AD(Rectt): ")]
    [DataType(DataType.Date)]
    [DisplayFormat(DataFormatString = "{0:yyyy-MM-dd}", ApplyFormatInEditMode = true)]
    public Nullable<System.DateTime> AD_Rectt { get; set; }

    [Display(Name = " Assistant: ")]
    [DataType(DataType.Date)]
    [DisplayFormat(DataFormatString = "{0:yyyy-MM-dd}", ApplyFormatInEditMode = true)]
    public Nullable<System.DateTime> Assistant_Rectt { get; set; }

    [Display(Name = " GM(HRD): ")]
    [DataType(DataType.Date)]
    [DisplayFormat(DataFormatString = "{0:yyyy-MM-dd}", ApplyFormatInEditMode = true)]
    public Nullable<System.DateTime> GM_HRD { get; set; }

    [Display(Name = " Send To: ")]
    public string Send_To { get; set; }

    [Display(Name = " Date: ")]
    [DataType(DataType.Date)]
    [DisplayFormat(DataFormatString = "{0:yyyy-MM-dd}", ApplyFormatInEditMode = true)]
    public Nullable<System.DateTime> Date { get; set; }

    [Display(Name = " Action: ")]
    public string Action { get; set; }

    [Display(Name = " Status: ")]
    public string Status { get; set; }

這是我的 actionResult 方法代碼

    public ActionResult NewFileToDiary(File_Movement fm)
    {
        if (ModelState.IsValid)
        {

            FileMovementManagementSystem.FileViewModel.FileViewModel fvm = new FileMovementManagementSystem.FileViewModel.FileViewModel();
            fvm.SaveNewFileMovement(fm);
            return RedirectToAction("UserDashBoard", "Home");
        }
        return View();
    }

這是 SaveNewFileMOvement 方法

    public void SaveNewFileMovement(File_Movement fm)
    {
        using (DiaryManagementSystemEntities db = new DiaryManagementSystemEntities())
        {

            db.File_Movement.Add(fm);
            db.SaveChanges();
        }
    }

Answer 1

我在您的文件移動類中看不到任何用戶選擇。 您只保存文件移動對象。 嘗試在您的控制器代碼中明確設置 User Id 以查看所需的結果。