我得到一个实体类型需要主键错误答案

【问题标题】：I got a the entity type requires primary key error我得到一个实体类型需要主键错误
【发布时间】：2022-11-30 17:07:23
【问题描述】：

当我尝试连接我的数据库和我的班级时，我收到了这个错误但是这个错误只出现在我的控制台、键盘鼠标和耳机表上。但是他们已经有了主键。

这是我的上下文类 `

public class EcommContext : DbContext
    {
        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            optionsBuilder.UseSqlServer(@"Server=.;Database=eCommerce;Trusted_Connection=true");

        }
        public DbSet<Product> Products { get; set; }
        public DbSet<Card> Cards { get; set; }
        public DbSet<Category> Categories { get; set; }
        public DbSet<Consoles> Consoles { get; set; }
        public DbSet<Headphone> Headphones { get; set; }
        public DbSet<Order> Orders { get; set; }
        public DbSet<OrderDetail> OrderDetails { get; set; }
        public DbSet<Mouse> Mouses { get; set; }
        public DbSet<MousePad> MousePads { get; set; }
        public DbSet<Keyboard> Keyboards { get; set; }
        public DbSet<KeyboardAndMouse> KeyboardMouse { get; set; }
        public DbSet<Gamepad> Gamepads { get; set; }
        public DbSet<Computer> Computers { get; set; }



    }

And my entity classes

    public class Headphone:IEntity
    {
        public int HeadphonesId { get; set; }
        public int ProductId { get; set; }
        public bool IsWireless { get; set; }
        public string Type { get; set; }
        public string Color { get; set; }
        public bool IsGaming { get; set; }
    }

    public class KeyboardAndMouse:IEntity
    {
        public int KmId { get; set; }
        public int ProductId { get; set; }
        public string Color { get; set; }
    }

    public class Consoles:IEntity
    {
        public int ConsoleId { get; set; }
        public int ProductId { get; set; }
        public string Color { get; set; }
        public int GamepadNumber { get; set; }
        public int Capacity { get; set; }
    }

我该如何解决。有人帮我吗？

【问题讨论】：

标签： c#

【解决方案1】：

在您的实体类中，您需要对主键字段使用 [Key] 注释。像下面这样尝试。

public class Headphone:IEntity
{
    [Key]
    public int HeadphonesId { get; set; }
}

public class KeyboardAndMouse:IEntity
{
    [Key]
    public int KmId { get; set; }
}

public class Consoles:IEntity
{
    [Key]
    public int ConsoleId { get; set; }
}

【讨论】：