数据库和代码之间的连接

我有一个错误：

One or more validation errors were detected during model generation:
'tSystem.Data.Entity.Edm.EdmEntityType: : EntityType 'DynamicMenu' has no key defined.    Define the key for this EntityType.
'tSystem.Data.Entity.Edm.EdmEntitySet: EntityType: EntitySet 'ambt_Dynamic_Menu' is based on type 'DynamicMenu' that has no keys defined.

在帮助程序类中，其代码是：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using Data.Models;
using Data;
namespace Ambermoda.Web
{
    public class MenuHelper
    {
        public static List<DynamicMenu> GetMenu()
        {
            DataContext db = new DataContext();
            List<DynamicMenu> list = db.ambt_Dynamic_Menu.ToList();
            return list;
        }
    }
}

所以我不知道如何解决它。我检查了(在我看来(可能产生此错误的所有内容，但有任何结果。

我是类似的帖子，但任何一个都不能解决我的问题。

如果有人有什么想法，请写:)

谢谢！

更多代码

动态菜单.cs

    [Table("abmt_Dynamic_Menu")]
    public class DynamicMenu
    {
        [DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
        public int dmn_id { get; set; }
        public string dmn_code { get; set; }
        public string dnm_parent_code { get; set; }
        public string dnm_title { get; set; }
        public string dnm_title_en { get; set; }
        public int dnm_order { get; set; }
    }

数据上下文.cs

public class DataContext : DbContext
{
    public DataContext() { }
    public DbSet<DynamicMenu> ambt_Dynamic_Menu { get; set; }
}

连接字符串：

<add name="DataContext" providerName="System.Data.SqlClient" connectionString="Data Source=Mikasasa-lap'Mikasasa;Database=Ambermoda;Integrated Security=True;Pooling=False;"/>

[Table("abmt_Dynamic_Menu")]
public class DynamicMenu
{
    [Key]
    [DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
    public int dmn_id { get; set; }
    public string dmn_code { get; set; }
    public string dnm_parent_code { get; set; }
    public string dnm_title { get; set; }
    public string dnm_title_en { get; set; }
    public int dnm_order { get; set; }
}