实体框架DbEntityValidationException - 找不到实体

Question

我想将我的注册表格中的数据发布到我的数据库中。起初，我有一个非常常见的错误“实体类型<model>不是当前上下文的模型的一部分” 。我解决了它，然后出现了另一个错误。所以现在出现的错误是在SaveChanges部分，它是“找不到实体密码”。我该如何解决这个问题？

这里是我的上下文的代码。

public partial class MyDbEntities : DbContext 
{ 
    public MyDbEntities() 
     : base("name=MyDbEntities") 
    { 
    } 

    protected override void OnModelCreating(DbModelBuilder modelBuilder) 
    { 
     modelBuilder.Entity<User>().ToTable("Users"); 
     modelBuilder.Entity<User>().Property(u => u.Name).IsRequired().HasMaxLength(256); 
     modelBuilder.Entity<User>().Property(u => u.Surname).IsRequired().HasMaxLength(256); 
     modelBuilder.Entity<User>().Property(u => u.Email).IsRequired().HasMaxLength(200); 
     modelBuilder.Entity<User>().Property(u => u.password).IsRequired().HasMaxLength(100); 
     modelBuilder.Entity<User>().Property(u => u.address).IsRequired(); 
     modelBuilder.Entity<User>().Property(u => u.postcode).IsRequired(); 
     modelBuilder.Entity<User>().Property(u => u.number).IsRequired(); 

    } 
    public override int SaveChanges() 
    { 
     try 
     { 
      return base.SaveChanges(); 
     } 
     catch (DbEntityValidationException ex) 
     { 
      string errorMessages = string.Join("; ", ex.EntityValidationErrors.SelectMany(x => x.ValidationErrors).Select(x => x.ErrorMessage)); 
      throw new DbEntityValidationException(errorMessages); 
     } 
    } 

    public virtual DbSet<User> Users { get; set; } 
} 

这里是我的控制器

[HttpPost] 
    [ValidateAntiForgeryToken] 
    public ActionResult Register(User U) 
    { 
     using(MyDbEntities db=new MyDbEntities()) 
     { 
      db.Users.Add(U); 
      db.SaveChanges(); 
      ModelState.Clear(); 
      U = null; 
      ViewBag.Message("Seccesfully stored"); 
     } 
     return View(U); 
    } 

的代码和模型 `

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

     [Required] 
     [Display(Name = "Surname")] 
     public string Surname { get; set; } 


     [Required] 
     [Display(Name = "Email")] 
     public string Email { get; set; } 

     [Required] 
     [DataType (DataType.Password)] 
     [StringLength(100, ErrorMessage = "The {0} must be at least {2} characters long.", MinimumLength = 6)] 
     [Display(Name = "Password")] 
     public string password { get; set; } 


     [Required] 
     [DataType(DataType.Password)] 
     [Display(Name = "Confirm Password")] 
     [Compare("Password", ErrorMessage = "The password and confirmation password do not match.")] 
     public string ConfirmPassword { get; set; } 


     [Required] 
     [Display(Name = "Address")] 
     public string address { get; set; } 

     [Required] 
     [Display(Name = "PostVode")] 
     [DataType(DataType.PostalCode)] 
     public string postcode { get; set; } 

     [Required] 
     [Display(Name = "Phone Number")] 
     public string number { get; set; } 

Answer 1

你需要确保User是属于你的DbContext。这是我有我的设置：

public partial class MyDbEntities : DbContext 
{ 
    public MyDbEntities() 
     : base("name=MyDbEntities") 
    { 
    } 

    protected override void OnModelCreating(DbModelBuilder modelBuilder) 
    { 
     // Add the mapping class in here, instead of the setup 
     modelBuilder.Configurations.Add(new UserMap()); 
    } 

    public override int SaveChanges() 
    { 
     try 
     { 
      return base.SaveChanges(); 
     } 
     catch (DbEntityValidationException ex) 
     { 
      string errorMessages = string.Join("; ", ex.EntityValidationErrors.SelectMany(x => x.ValidationErrors).Select(x => x.ErrorMessage)); 
      throw new DbEntityValidationException(errorMessages); 
     } 
    } 

    public virtual DbSet<User> Users { get; set; } 
} 

用户映射类，注意从EntityTypeConfiguration<User>继承，我认为这是你错过了位：

public class UserMap : EntityTypeConfiguration<User> 
{ 
    public UserMap() 
    { 
     // Your original setup goes here 
     this.ToTable("Users"); 
     this.Property(u => u.Name).IsRequired().HasMaxLength(256); 
     this.Property(u => u.Surname).IsRequired().HasMaxLength(256); 
     this.Property(u => u.Email).IsRequired().HasMaxLength(200); 
     this.Property(u => u.password).IsRequired().HasMaxLength(100); 
     this.Property(u => u.address).IsRequired(); 
     this.Property(u => u.postcode).IsRequired(); 
     this.Property(u => u.number).IsRequired(); 
    } 
} 

如果不是这样，或者这可能是你错过了。我的DbContext有一个静态构造函数设置数据库初始化程序，如果你没有它已经，尝试添加它：

static MyDbEntities() 
{ 
    Database.SetInitializer<MyDbEntities>(null); 
}