在模型生成期间检测到一个或多个验证错误:\r\n\r\n

Question

我很困惑。我正在构建一个级联下拉列表，但我收到了最奇怪的错误。我不断收到以下错误（很长）-

“在模型生成期间检测到一个或多个验证错误：\r\n\r\nAQB_MON.ViewModels.DeviceStatu: : EntityType 'DeviceStatu' 没有定义键。定义此 EntityType 的键。\r \nAQB_MON.ViewModels.SelectListItem: : EntityType 'SelectListItem' 没有定义键。定义此 EntityType 的键。\r\nDeviceStatus: EntityType: EntitySet 'DeviceStatus' 基于没有定义键的类型 'DeviceStatu'。\r \nSelectListItems: EntityType: EntitySet 'SelectListItems' 基于没有定义键的类型 'SelectListItem'。\r\n"}

我有一个制造商表和一个制造商模型表。我的级联下拉列表包括用户首先选择制造商，然后相应的模型选项将在第二个下拉列表中可用。但是，在尝试加载下拉列表时，我一直收到错误消息。

我创建了自己的 ViewModel - ManufacturerModelContext

public class ManufacturerModelContext : DbContext
{

    public DbSet<Manufacturer> Manufacturers { get; set; }
    public DbSet<ManufacturerModel> ManufacturerModels { get; set; }
}

然后我用

检索制造商和型号

//Populate the cascading dropdowns for manufacturer and model
    ManufacturerModelContext mm = new ManufacturerModelContext();
    [HttpGet]
    public JsonResult GetManufacturers()
    {

        var manufacturer = from a in mm.Manufacturers
                           select a.Manufacturer1;

        return Json(manufacturer.ToList(), JsonRequestBehavior.AllowGet);

    }

    public JsonResult GetModelsByManufacturerID(string manufacturerId)
    {

        int Id = Convert.ToInt32(manufacturerId);

        var models = from a in mm.ManufacturerModels where a.ManufacturerID == Id select a;

        return Json(models);
    }

Var 制造商 失败。最奇怪的是，我什至没有也从未有过 AQB_MON.ViewModels.DeviceStatu

制造商模型

public partial class Manufacturer
{
    public Manufacturer()
    {
        this.ManufacturerModels = new HashSet<ManufacturerModel>();
    }

    public int ManufacturerID { get; set; }
    [Display(Name="Manufacturer")]
    public string Manufacturer1 { get; set; }
    [Display(Name="Manufacturer Description")]
    public string ManufacturerDescription { get; set; }
    public System.DateTime DATE_CREATED { get; set; }
    public string CREATED_BY { get; set; }
    public Nullable<System.DateTime> DATE_MODIFIED { get; set; }
    public string MODIFIED_BY { get; set; }

    public virtual ICollection<ManufacturerModel> ManufacturerModels { get; set; }

ManufacturerModel 型号

public partial class ManufacturerModel
{
    public ManufacturerModel()
    {
        this.Devices = new HashSet<Device>();
    }

    public int ManufacturerModelID { get; set; }
    [Display(Name="Manufacturer")]
    public int ManufacturerID { get; set; }
    public string Model { get; set; }
    [Display(Name="Model Description")]
    public string ModelDescription { get; set; }
    public System.DateTime DATE_CREATED { get; set; }
    public string CREATED_BY { get; set; }
    public Nullable<System.DateTime> DATE_MODIFIED { get; set; }
    public string MODIFIED_BY { get; set; }

    public virtual ICollection<Device> Devices { get; set; }
    public virtual Manufacturer Manufacturer { get; set; }

设备型号

 public partial class Device
{
    public Device()
    {
        this.DeviceLocations = new HashSet<DeviceLocation>();
        this.DeviceLogs = new HashSet<DeviceLog>();
        this.DeviceStatus = new HashSet<DeviceStatu>();
    }


    public int DeviceID { get; set; }
    [Display(Name = "Device Type")]
    public int DeviceTypeID { get; set; }
    public int ManufacturerModelID { get; set; }
    [Display(Name="Inventory Number")]
    public string InventoryNumber { get; set; }
    [Display(Name = "Serial Number")]
    public string SerialNumber { get; set; }
    [Display(Name = "State ID")]
    public string StateID { get; set; }
    [Display(Name = "Date Received")]
    [DisplayFormat(DataFormatString = "{0:d}", ApplyFormatInEditMode = true)]
    public DateTime? DateReceived { get; set; }
    public Nullable<decimal> Price { get; set; }
    public string Notes { get; set; }
    public System.DateTime DATE_CREATED { get; set; }
    public string CREATED_BY { get; set; }
    public Nullable<System.DateTime> DATE_MODIFIED { get; set; }
    public string MODIFIED_BY { get; set; }


    public virtual DeviceType DeviceType { get; set; }
    public virtual ManufacturerModel ManufacturerModel { get; set; }
    public virtual ICollection<DeviceLocation> DeviceLocations { get; set; }
    public virtual ICollection<DeviceLog> DeviceLogs { get; set; }
    public virtual ICollection<DeviceStatu> DeviceStatus { get; set; }

Answer 1

这可能是错误消息所说的：EntityType 'DeviceStatu' has no key defined。定义此 EntityType 的键。

很难说，因为您没有发布此实体的数据模型，但这可能是命名问题

要成为键，字段必须与类同名，如 DeviceStatusId 或使用字段上方的 [Key] 数据注释