在 asp.net mvc 中插入后表不递增

Question

我正在开发一个 ASP.NET MVC 项目。我已经创建了在我的项目中使用的各种模型和视图模型。我还使用种子数据为我的数据库表播种，但在实现注册视图时，我测试了表单，但得到 0 作为插入数据库表的 Id 部分的值。我截断了表格并做了一个新的插入，但仍然有同样的错误。

下面是用户表的模型

public class User
{
    [Key]
    public byte Id { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string Email { get; set; }
    public string RefIndicator { get; set; }
    public Team TeamCategory { get; set; }
    public byte TeamId { get; set; }
    public bool IsRegistered { get; set; }
    public DateTime DateRegistered { get; set; }
    public DateTime? LastModified { get; set; }
    public UserRoles UserRoles { get; set; }
    public byte UserRolesId { get; set; }
}

下面是我为需要在视图中使用的团队模型属性创建的视图模型

public class RegisterFormViewModel
{
    public User Users { get; set; }
    public byte Id { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string Email { get; set; }
    public IEnumerable<Team> Teams { get; set; }
    public byte TeamId { get; set; }
    public string RefIndicator { get; set; }
    public bool IsRegistered { get; set; }
    public DateTime DateRegistered { get; set; }
    public byte UserRolesId { get; set; }
}

这是用户控制器的注册操作，用于初始化注册视图的值

public ActionResult Register()
{
    var AppUser = User.Identity.Name.Substring(5);
    var AppUserEmail = AppUser + "@nlng.com";
    int index = AppUser.IndexOf('.');
    var FirstName = AppUser.Substring(0, index);
    var LastName = AppUser.Substring(index + 1);
    var IsRegistered = true;
    var UserRolesId = 1;
    var DateRegistered = HttpContext.Timestamp;

    var teams = _context.Team.ToList();

    var viewModel = new RegisterFormViewModel{
        Email = AppUserEmail,
        FirstName = FirstName,
        LastName = LastName,
        Teams = _context.Team.ToList(),
        IsRegistered = IsRegistered,
        UserRolesId = (byte)UserRolesId,
        DateRegistered = DateRegistered               
    };

    return View("Register", viewModel);
}

最后是注册页面的关联视图

@model eLeave.ViewModel.RegisterFormViewModel
@{
    ViewBag.Title = "Register";
    Layout = "~/Views/Shared/_Layout.cshtml";
}

<h2>User Registration</h2>

@using (Html.BeginForm("Save", "User"))
{
    <div class="form-group">
        @Html.LabelFor(r=>r.FirstName)
        @Html.TextBoxFor(r => r.FirstName, new { @class = "form-control", @readonly = true })
    </div>

    <div class="form-group">
        @Html.LabelFor(r => r.LastName)
        @Html.TextBoxFor(r => r.LastName, new { @class = "form-control", @readonly = true })
    </div>

    <div class="form-group">
        @Html.LabelFor(r => r.Email)
        @Html.TextBoxFor(r => r.Email, new { @class = "form-control", @readonly = true })
    </div>

    <div class="form-group">
        @Html.LabelFor(r => r.TeamId)
        @Html.DropDownListFor(r => r.TeamId, new SelectList(Model.Teams, "Id", "TeamName"), "Select your Team", new { @class = "form-control" })
    </div>

    <div class="form-group">
        @Html.LabelFor(r => r.RefIndicator)
        @Html.TextBoxFor(r => r.RefIndicator, new { @class = "form-control" })
    </div>

    @Html.HiddenFor(m => m.IsRegistered)
    @Html.HiddenFor(m => m.DateRegistered)
    @Html.HiddenFor(m => m.UserRolesId)
    @Html.HiddenFor(m => m.Id)
@Html.AntiForgeryToken()
        <button class="btn btn-primary">Register</button>
    }

最后是 userController 的保存动作

[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Save(User user)
{
    if (!ModelState.IsValid)
    {
        var viewModel = new RegisterFormViewModel
        {
            Users = user,
            Teams = _context.Team.ToList()
        };

        return View("Register", viewModel);
    }

    if (user.Id == 0)
    {
        _context.User.Add(user);
    }
    else
    {
        var usersInDb = _context.User.Single(m => m.Id == user.Id);
        usersInDb.FirstName = user.FirstName;
        usersInDb.LastName = user.LastName;
        usersInDb.TeamCategory = user.TeamCategory;
        usersInDb.RefIndicator = user.RefIndicator;
        usersInDb.UserRoles = user.UserRoles;
        usersInDb.IsRegistered = user.IsRegistered;
        usersInDb.Email = user.Email;
        usersInDb.DateRegistered = user.DateRegistered;
    }

    _context.SaveChanges();

    return RedirectToAction("Index", "User");
}

Save Action 基本上做了两件事......它保存了一个新表单，也用于更新数据。

如果我的代码中的错误可以被找出来，我们将不胜感激。

Answer 1

据我了解，您需要将 ID 设为自动递增值。

public class User
{
    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int Id { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string Email { get; set; }
    public string RefIndicator { get; set; }
    public Team TeamCategory { get; set; }
    public byte TeamId { get; set; }
    public bool IsRegistered { get; set; }
    public DateTime DateRegistered { get; set; }
    public DateTime? LastModified { get; set; }
    public UserRoles UserRoles { get; set; }
    public byte UserRolesId { get; set; }
}

我认为它不适用于byte，但您可以肯定地使用int。

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{        
    modelBuilder.Entity<User>().Property(a => a.Id).HasKey(b => b.Id);
    modelBuilder.Entity<User>().Property(a => a.Id).HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity);
}