MVC标识-INSERT语句与FOREIGN KEY约束冲突

Question

我知道这个问题已经讨论过几次了，但这个问题与内置的Identity模型有关。

我创建了一个名为"公司"的自定义模型。注册新用户时，我还想选择公司名称。

我已经将所需的数据添加到RegisterViewModel中，视图和表单将按原样显示。我已经在Company表中为2个公司设定了种子，因此该值不应为空。

public class RegisterViewModel
{        
   ... Removed some irrelevant code ...
    [Required(ErrorMessage = "You must select a company name.")]
    [Display(Name = "Company")]
    public int CompanyID { get; set; }
    public virtual Company ApplicationUser_Company { get; set; }

当我想插入一个带有以下错误的新用户时，问题就出现了：

The INSERT statement conflicted with the FOREIGN KEY constraint "FK_dbo.AspNetUsers_dbo.Companies_CompanyID". The conflict occurred in database "aspnet-ProjectMed-20160327120257", table "dbo.Companies", column 'CompanyID'.
The statement has been terminated. 

检查帐户控制器我看不到任何问题：

    // GET: /Account/Register
    [AllowAnonymous]
    public ActionResult Register()
    {
        ViewBag.CompanyID = new SelectList(db.Companies, "CompanyID", "Company_Name");
        return View();
    }
    //
    // POST: /Account/Register
    [HttpPost]
    [AllowAnonymous]
    [ValidateAntiForgeryToken]
    public async Task<ActionResult> Register(RegisterViewModel model)
    {
        if (ModelState.IsValid)
        {
            var user = new ApplicationUser { UserName = model.Email, Email = model.Email, ApplicationUser_FirstName = model.ApplicationUser_FirstName, ApplicationUser_LastName = model.ApplicationUser_LastName, ApplicationUser_Company = model.ApplicationUser_Company };
                var result = await UserManager.CreateAsync(user, model.Password); <<<---- This is where the error occurs <<<---
                if (result.Succeeded)
                {
                    await SignInManager.SignInAsync(user, isPersistent: false, rememberBrowser: false);
                    return RedirectToAction("Index", "Home");
                }
                AddErrors(result);
        }
        // If we got this far, something failed, redisplay form
        return View(model);
    }

我也在复制SQL表：

AspNetUsers表：

CREATE TABLE [dbo].[AspNetUsers] (
    [Id]                        NVARCHAR (128) NOT NULL,
    [ApplicationUser_FirstName] NVARCHAR (50)  NOT NULL,
    [ApplicationUser_LastName]  NVARCHAR (50)  NOT NULL,
    [CompanyID]                 INT            NOT NULL,
    [Email]                     NVARCHAR (256) NULL,
    [EmailConfirmed]            BIT            NOT NULL,
    [PasswordHash]              NVARCHAR (MAX) NULL,
    [SecurityStamp]             NVARCHAR (MAX) NULL,
    [PhoneNumber]               NVARCHAR (MAX) NULL,
    [PhoneNumberConfirmed]      BIT            NOT NULL,
    [TwoFactorEnabled]          BIT            NOT NULL,
    [LockoutEndDateUtc]         DATETIME       NULL,
    [LockoutEnabled]            BIT            NOT NULL,
    [AccessFailedCount]         INT            NOT NULL,
    [UserName]                  NVARCHAR (256) NOT NULL,
    CONSTRAINT [PK_dbo.AspNetUsers] PRIMARY KEY CLUSTERED ([Id] ASC),
    CONSTRAINT [FK_dbo.AspNetUsers_dbo.Companies_CompanyID] FOREIGN KEY ([CompanyID]) REFERENCES [dbo].[Companies] ([CompanyID]) ON DELETE CASCADE
);
GO
CREATE NONCLUSTERED INDEX [IX_CompanyID]
    ON [dbo].[AspNetUsers]([CompanyID] ASC);
GO
CREATE UNIQUE NONCLUSTERED INDEX [UserNameIndex]
    ON [dbo].[AspNetUsers]([UserName] ASC);

公司表：

CREATE TABLE [dbo].[Companies] (
    [CompanyID]          INT            IDENTITY (1, 1) NOT NULL,
    [Company_Name]       NVARCHAR (50)  NOT NULL,
    [Company_Code]       NVARCHAR (9)   NOT NULL,
    [Company_Address1]   NVARCHAR (100) NOT NULL,
    [Company_Address2]   NVARCHAR (100) NULL,
    [Company_PostalCode] NVARCHAR (15)  NOT NULL,
    [Company_City]       NVARCHAR (50)  NOT NULL,
    [CountryID]          INT            NOT NULL,
    [Company_CLOG]       BIT            NOT NULL,
    [Company_SubAgent]   BIT            NOT NULL,
    CONSTRAINT [PK_dbo.Companies] PRIMARY KEY CLUSTERED ([CompanyID] ASC),
    CONSTRAINT [FK_dbo.Companies_dbo.Countries_CountryID] FOREIGN KEY ([CountryID]) REFERENCES [dbo].[Countries] ([CountryID]) ON DELETE CASCADE
);

GO
CREATE UNIQUE NONCLUSTERED INDEX [IX_Company_Code]
    ON [dbo].[Companies]([Company_Code] ASC);

GO
CREATE NONCLUSTERED INDEX [IX_CountryID]
    ON [dbo].[Companies]([CountryID] ASC);

有什么想法吗？这里出了什么问题？

Answer 1

Gut告诉我它在这行以内（为了清晰/评论而分开）：

var user = new ApplicationUser
{
  UserName = model.Email,
  Email = model.Email,
  ApplicationUser_FirstName = model.ApplicationUser_FirstName,
  ApplicationUser_LastName = model.ApplicationUser_LastName,
  ApplicationUser_Company = model.ApplicationUser_Company      // <--
};

基本上，当在表单操作之间传递实体引用时，您希望引用ID（因为整个实体不会跨线传输，也不应该出于安全目的（格式错误的输入、黑客攻击等））

您的ViewModel（在本例中，RegisterViewModel实际上应该只有CompanyID（它是Company实体的PK）。然后应该使用它通过执行查找然后分配给user来填充新用户ApplicationUser（user）。例如

[HttpPost]
public async Task<ActionResult> Register(RegisterViewModel model)
{
  // verify the models' valid
  if (ModelState.IsValid)
  {
    // Perform a lookup to retrieve the selected company
    var company = db.COmpanies.SingleOrDefault(x => x.CompanyID == model.CompanyID);
    if (company != null) // Found it
    {
      // No go on to establish an application user
      var user = new ApplicationUser {
        /* ... */,
        ApplicationUser_Company = company // entity we retrieved
      };
      //
      // SignInManager yatta yata
      //
    }
  }
  return View(model); // Uh-oh fallback.
}

不过请注意，如果您的ApplicationUser实体有两个属性（大多数都有），一个用于ID，另一个用于外部关系；例如

public int CompanyID { get; set; } // ID property
[ForeignKey("CompanyID")]
public virtual Company Company { get; set; } // entity property

您只需要指定其中一个/或。在这种情况下，在填充ApplicationUser之前不需要执行查找，只需设置user.CompanyID = model.CompanyID;

Answer 2

由于你上次的建议，我似乎发现了错误！如果ID…

对我有用的代码：

[HttpPost]
public async Task<ActionResult> Register(RegisterViewModel model)
{
  // verify the models' valid
  if (ModelState.IsValid)
  {
      var user = new ApplicationUser {
        /* ... */,
        CompanyID = model.CompanyID // entity we retrieved
      };
      //
      // SignInManager yatta yata
      //
  }
  return View(model); // Uh-oh fallback.
}