尝试使用组合键更新表时出现DbUpdateConcurrencyException

Question

Im using Visual Studio 2015 with MVC5.

I try build a edit view to a table with this code, and i get a error that I can´t solve

        @Html.HiddenFor(model => model.GHE_CORRELATIVO)*@

    <div class="form-group">
        @Html.LabelFor(model=> model.COP_CORRELATIVO,"COP_CORRELATIVO")
        @Html.DropDownList("COP_CORRELATIVO", null, htmlAttributes: new { @class = "form-control" })

    </div>

    <div class="form-group">
        @Html.LabelFor(model => model.GHE_DESCRIPCION, htmlAttributes: new { @class = "control-label col-md-2" })
        <div class="col-md-10">
            @Html.EditorFor(model => model.GHE_DESCRIPCION, new { htmlAttributes = new { @class = "form-control" } })
            @Html.ValidationMessageFor(model => model.GHE_DESCRIPCION, "", new { @class = "text-danger" })
        </div>
    </div>

DbUpdateConcurrencyExcepcion when the data is received by the controller.

[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Edit([Bind(Include = "COP_CORRELATIVO,GHE_CORRELATIVO,GHE_DESCRIPCION")] GRUPO_HERRAMIENTA gRUPO_HERRAMIENTA)
{
    if (ModelState.IsValid)
    {
        db.Entry(gRUPO_HERRAMIENTA).State = EntityState.Modified;
        db.SaveChanges();
        return RedirectToAction("Index");
    }
    ViewBag.COP_CORRELATIVO = new SelectList(db.CLASIFICACION_OPCION, "COP_CORRELATIVO", "COP_DESCRIPCION", gRUPO_HERRAMIENTA.COP_CORRELATIVO);
    return View(gRUPO_HERRAMIENTA);
}

My table is composed by two pk, ghe_correlativo (own) and cop_correlativo (FK), the scaffold only generate the text input but I need editing the cop_correlativo field with a dropdown fiel.

The structure of model :

   public partial class GRUPO_HERRAMIENTA
    {
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
        public GRUPO_HERRAMIENTA()
        {
            this.PERFIL_INTRANET = new HashSet<PERFIL_INTRANET>();
        }

        public int COP_CORRELATIVO { get; set; }
        public int GHE_CORRELATIVO { get; set; }
        public string GHE_DESCRIPCION { get; set; }

        public virtual CLASIFICACION_OPCION CLASIFICACION_OPCION { get; set; }
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
        public virtual ICollection<PERFIL_INTRANET> PERFIL_INTRANET { get; set; }
    }

what am I doing wrong?

Answer 1

In debug, make sure that all parameters are being set in the post action, specially COP_CORRELATIVO , which is the primary key.

For testing puposes, instead of db.Entry(gRUPO_HERRAMIENTA).State = EntityState.Modified; use this:

db.GRUPO_HERRAMIENTAS.Attach(gRUPO_HERRAMIENTA); 

db.Entry(gRUPO_HERRAMIENTA).Property(i => i.COP_CORRELATIVO ).IsModified = true;
db.Entry(gRUPO_HERRAMIENTA).Property(i => i.GHE_CORRELATIVO ).IsModified = true;
db.Entry(gRUPO_HERRAMIENTA).Property(i => i.GHE_DESCRIPCION ).IsModified = true;