使用 EF 模型在 mvc 中创建/更新不起作用

Question

我在我的 MVC 应用程序中使用现有的 sql 数据库。对于其中一张表，创建/更新功能不起作用。我假设这是因为我的应用程序无法检索在 SQL 中定义的自动生成的 ID，因此将空值插入到不可为空的字段中，从而导致应用程序中断。所以，我的问题是如何检索在我的 sql 数据库中定义的自动生成字段以显示在我的 MVC5 应用程序中。非常感谢任何可以提供帮助的人。

下面是我的客户数据库表：

模型：

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

    public int CustomerID { get; set; }
    public int DiscountLevelID { get; set; }
    public int LoyaltyLevelID { get; set; }
    public string CustomerCompanyName { get; set; }
    public string CustomerName { get; set; }
    public string CustomerSurname { get; set; }

    [DatabaseGenerated(DatabaseGeneratedOption.Computed)]
    public string CustomerGUID { get; set; }
    public int CustomerStatus { get; set; }
    public string CustomerAddress { get; set; }
    public string CustomerTel { get; set; }
    public string CustomerCel { get; set; }
    public Nullable<int> CustomerNumber { get; set; }
    public string CustomerContact { get; set; }
    public string CustomerLogo { get; set; }
    public string CustomerLogoPath { get; set; }
    public int LastStoreCustomerSyncID { get; set; }

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

控制器：

[HttpPost]
    [ValidateAntiForgeryToken]
    public ActionResult Create([Bind(Include = "CustomerID,DiscountLevelID,LoyaltyLevelID,CustomerCompanyName,CustomerName,CustomerSurname,CustomerGUID,CustomerStatus,CustomerAddress,CustomerTel,CustomerCel,CustomerNumber,CustomerContact,CustomerLogo,CustomerLogoPath,LastStoreCustomerSyncID")] Customer customer)
    {
        if (ModelState.IsValid)
        {
            db.Customers.Add(customer);
            db.SaveChanges();
            return RedirectToAction("Index");
        }

        return View(customer);
    }

    // GET: Companies/Edit/5
    public ActionResult Edit(int? id)
    {
        if (id == null)
        {
            return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
        }
        Customer customer = db.Customers.Find(id);
        if (customer == null)
        {
            return HttpNotFound();
        }
        return View(customer);
    }

    // POST: Companies/Edit/5

    [HttpPost]
    [ValidateAntiForgeryToken]
    public ActionResult Edit([Bind(Include = "CustomerID,DiscountLevelID,LoyaltyLevelID,CustomerCompanyName,CustomerName,CustomerSurname,CustomerGUID,CustomerStatus,CustomerAddress,CustomerTel,CustomerCel,CustomerNumber,CustomerContact,CustomerLogo,CustomerLogoPath,LastStoreCustomerSyncID")] Customer customer)
    {
        if (ModelState.IsValid)
        {
            db.Entry(customer).State = EntityState.Modified;
            db.SaveChanges();
            return RedirectToAction("Index");
        }
        return View(customer);
    }

观点

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

Answer 1

所以，我的问题是如何检索自动生成的字段 在我的 sql 数据库中定义以显示在我的 MVC5 应用程序中。

按照步骤进行

• 右键单击 EDMX 设计器的设计器表面，然后单击 Update Model From Database...

默认情况下会刷新所有实体，仅当您选择它们​​时才会添加新实体。

编辑：如果它不能很好地刷新。 选择 EDMX 设计器中的所有表和视图。 删除它们。 然后，从数据库更新模型

• 右键单击Model1.tt 并选择“Run Custom Tool”保存并立即构建，看看生成的类。 右键单击 On Model1.Context.tt 并选择“Run Custom Tool”保存并构建现在看到属性 IN Context 类的生成类似于

附言

也请阅读此链接，它非常有用：http://blog.jongallant.com/2012/08/entity-framework-manual-update/

Answer 2

您应该将 CustomerID 作为参数传递给 Controller。不要向 CustomerID 授予空值权限并将其设为 AUTO_INCREMENT

<div class="form-group">
    @Html.TextBoxFor(model => model.CustomerID, new {style = 'display:none'})
    @Html.LabelFor(model => model.CustomerGUID, htmlAttributes: new { @class = "control-label col-md-2" })
    <div class="col-md-10">
        @Html.EditorFor(model => model.CustomerGUID, new { htmlAttributes = new { @class = "form-control" } })
        @Html.ValidationMessageFor(model => model.CustomerGUID, "", new { @class = "text-danger" })
    </div>
</div>