删除在另一个 table Entity Framework 中作为 fk 的对象

Question

我正在尝试删除在另一个 table 中引用的对象。

我要删除的对象：

 [Table("Local")]
public class Local
{
    [Key]
    public int Id { get; set; }
    public string ViejoId { get; set; }
    [Required]
    [Index("UniqueNuevoId", 1, IsUnique = true)]
    [Display(Name ="Nuevo Id")]
    public int NuevoId { get; set; }
    [Display(Name ="Id Unificado")]
    public string UnificadoCon { get; set; }
    [Required(ErrorMessage = "Es necesario agregar el nombre del comercio")]
    [Display(Name = "Comercio")]
    public string NombreComercio { get; set; }
    [Display(Name = "Nom Unificado")]
    public string NombreComercioUnificado { get; set; }
    [Required]
    public string Direccion { get; set; }
    [Required]
    [Display(Name ="Tel")]
    public string Telefono { get; set; }
    [Required]
    public string Provincia { get; set; }
    [Required]
    public string Localidad { get; set; }
    public Proveedor Proveedor { get; set; }
    public Estado Estado { get; set; }

    public DateTime FechaIngreso = DateTime.Today;
    public bool Bonificado { get; set; }
    public bool Premium { get; set; }

    [Display(Name ="Instalación")]
    [DataType(DataType.Date)]
    public DateTime FechaInstalacion { get; set; }
    public virtual List<NotasAdjuntas> notas { get; set; }

关联的对象

[Table("NotasAdjuntas")]
public class NotasAdjuntas
{
    public int Id { get; set; }

    [Required]
    [MinLength(3)]
    [MaxLength(20)]
    public string Asunto { get; set; }
    [Required]
    public string Detalle { get; set; }
    [DataType(DataType.Date)]
    public DateTime Fecha { get; set; }
    [DataType(DataType.Time)]
    public DateTime Hora { get; set; }
    public  virtual Local local { get; set; }
    public virtual string username { get; set; }

}

我想删除 "Local"，但我知道如果我想这样做，首先我必须删除 "NotasAdjuntas"。

这是我的控制器 (LocalsController)

 // GET: Locals/Delete/5
    public ActionResult Delete(int? id)
    {
        if (id == null)
        {
            return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
        }
        Local local = db.Locales.Find(id);
        if (local == null)
        {
            return HttpNotFound();
        }
        return View(local);
    }

    // POST: Locals/Delete/5
    [HttpPost, ActionName("Delete")]
    [ValidateAntiForgeryToken]
    public ActionResult DeleteConfirmed(int id)
    {
        Local local = db.Locales.Find(id);
        db.Locales.Remove(local);
        db.SaveChanges();
        return RedirectToAction("Index");
    }

感谢任何帮助！

Answer 1

在删除 Local 之前删除注释条目。像这样：

public ActionResult DeleteConfirmed(int id)
{
    foreach (var nota in local.notas)
    {
        var notaParaEliminar = db.NotasAdjuntas.find(nota.Id);
        db.NotasAdjuntas.Remove(notaParaEliminar);
    }
    Local local = db.Locales.Find(id);
    db.Locales.Remove(local);
    db.SaveChanges();
    return RedirectToAction("Index");
}

Answer 2

您只需将 "local" 标记为必需的属性即可（EF 将生成正确的关系 - 在本例中为一对多）。意思是，如果您正确设置关系，它会为您自动删除 "child" 个实体。

[Table("NotasAdjuntas")]
public class NotasAdjuntas
{
    public int Id { get; set; }
    ....
    [Required]  //<<<<< add this
    public virtual Local local { get; set; }
    ....
}

删除在另一个 table Entity Framework 中作为 fk 的对象

Delete an object that is a fk in another table Entity Framework

c#

asp.net-mvc

entity-framework