“INSERT语句冲突与外键约束

Question

错误消息：

The INSERT statement conflicted with the FOREIGN KEY constraint "FK_UserProfile_UserLogin". The conflict occurred in database "ToDoDB", table "dbo.UserLogin", column 'UserLoginID'. The statement has been terminated.

这到底意味着什么

我试图建立和配置文件MVC5 web应用程序我创建了一个简单的日志我的？ 。表中的SQL Express

首先，这里是我的注册页面模型：

public class UserSignUp 
{ 
    [Key] 
    public int UserLoginID { get; set; } 

    //Foregin key for the login table - First name, last name, creation date, and email 
    public int UserProfileID { get; set; } 

    [Required(ErrorMessage = "Username is required")] 
    [Display(Name = "Username")] 
    public string Username { get; set; } 

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

    [Required(ErrorMessage = "First Name is required")] 
    [Display(Name = "First Name")] 
    public string FirstName { get; set; } 

    [Required(ErrorMessage = "Last Name is required")] 
    [Display(Name = "Last Name")] 
    public string LastName { get; set; } 

    [DataType(DataType.DateTime)] 
    public DateTime CreationDate { get; set; } 

    [Required(ErrorMessage = "Valid email is required")] 
    [DataType(DataType.EmailAddress)] 
    public string Email { get; set; } 
} 

因此，UserLoginID是UserLogin表中的主键，而UserProfileID是UserProfile表中的主键。我将UserProfile表的外键从UserLogin设置为UserLoginID。

这里是我创建新用户模型：

public class UserProfileManager 
{ 
    public void AddUserAccount(UserSignUp newUser) 
    { 
     // create database connection 
     using (ToDoDBEntities db = new ToDoDBEntities()) 
     { 
      // Collect viewmodel data 
      // Here building goes by object type and not foregin key relationship 
      UserLogin UL = new UserLogin(); 
      UL.Username = newUser.Username; 
      UL.Password = newUser.Password; 

      // Add the UserLogin object I just built to the database 
      db.UserLogins.Add(UL); 
      db.SaveChanges(); 

      UserProfile UP = new UserProfile(); 
      // establish connection to UL by establishing foreign key relationship 
      UP.UserLoginID = newUser.UserLoginID; 
      UP.FirstName = newUser.FirstName; 
      UP.LastName = newUser.LastName; 
      UP.CreationDate = newUser.CreationDate; 
      UP.Email = newUser.Email; 

      // Add UserProfile object to databse and save changes 
      db.UserProfiles.Add(UP); 
      db.SaveChanges(); 
     } 
    } 

    //Check if user is real before login is allowed 
    public bool isLoginReal(string LoginName) 
    { 
     using (ToDoDBEntities DB = new ToDoDBEntities()) 
     { 
      // Return the user from the DB whose login name matches the LoginName string passed in as perameter 
      return DB.UserLogins.Where(o => o.Username.Equals(LoginName)).Any(); 
     } 
    } 
} 

我AddUserAccount是我觉得我有问题。因此，我首先构建UserLogin对象并添加并保存到数据库。这似乎实际上解决了。但是下一步，我构建，添加和保存对象似乎不起作用。至少数据库不会更新。

这里是控制器处理操作：

public class AccountController : Controller 
{ 
    // GET: Account 
    public ActionResult Index() 
    { 
     return View(); 
    } 

    #region signup methods 
    // Get method for signup page 
    public ActionResult SignUpPage() 
    { 
     return View(); 
    } 

    // Post method for signup page - post to db 
    [HttpPost] 
    // Pass in the UserSign up model object to be built 
    public ActionResult SignUpPage(UserSignUp USUV) 
    { 
     // Form is filled out and then method is entered 
     if (ModelState.IsValid) 
     { 
      // Form is filled out and database connection is established if form is valid 
      UserProfileManager UPM = new UserProfileManager(); 

      if (!UPM.isLoginReal(USUV.Username)) 
      { 
       // data access . adduseraccount from entity manager (where model objects are built) 
       UPM.AddUserAccount(USUV); 
       FormsAuthentication.SetAuthCookie(USUV.FirstName, false); 
       return RedirectToAction("Welcome", "Home"); 
      } 
      else 
      { 

      } 
     } 
     return View(); 
    } 
    #endregion 
} 

要我（小白）眼睛一切正常。收到SignUpPage，然后新的UserSignUp对象被传递到Post操作中，并且实体框架对象（UserProfileManager）被构建，表单被认证并且用户被重定向到Welcome视图，或者用户被返回到注册视图。

有人可以帮助我找出我要么失踪或做错的机会吗？我包括了一个数据库设计的参考图片（我对数据库和MVC的了解甚少）。

Answer 1

是啊，以后的问题就在这里：

UP.UserLoginID = newUser.UserLoginID; 

这不是newUser，它应该是：

UP.UserLoginID = UL.UserLoginID; 

因为你刚才添加的对象UL到数据库，要获取插入对象的生成ID，您必须调用它，而不是newUser对象。