实体框架关系——sql错误

Question

我有一个项目，我正在尝试实现一个（看似）简单的购物车。以下是相关实体。我经常遇到各种错误，这与 order_Id 列名无效有关。所以我怀疑订单和项目之间的关系有问题，但我也认为在方法方面我可能遗漏了一些更大的东西。任何意见，将不胜感激。

public class Item
{
    public int Id { get; set; }
    public byte[] Thumbnail { get; set; }
    public decimal Price { get; set; }
    public string Name { get; set; }
    public bool OnSale { get; set; }
    public string Description { get; set; }
}
public class Order
{
    public int Id { get; set; }
    [ForeignKey("User")]
    public virtual int UserId { get; set; }
    public string Country { get; set; }
    public decimal Total { get; set; }
    public System.DateTime OrderDate { get; set; }
    public virtual IList<Item> Items { get; set; }
    public virtual User User { get; set; }
}
public class MyCart
{
    [Key]
    [ForeignKey("User")]
    public int UserId { get; set; }
    public virtual User User { get; set; }
    public string MyCartId { get; set; }
    public IDictionary<Item, int> ItemsHash { get; set; }      
}

public class User
{
    public int Id{ get; set; }
    public int CreditCard { get; set; }
    public string Country { get; set; }
    public int CCExpMonth { get; set; }
    public int CCExpYear { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }

    public virtual IList<Order> Orders { get; set; }
    public virtual MyCart Cart { get; set; }
}

Answer 1

我更正您的实体如下：

public class Item
{
    public int Id { get; set; }

    public virtual int OrderId { get; set; }

    [ForeignKey("OrderId")]
    [InverseProperty("Items")]
    public virtual Order Order { get; set; }
}

public class Order
{
    public int Id { get; set; }

    public virtual int UserId { get; set; }

    [ForeignKey("UserId")]
    [InverseProperty("Orders")]
    public virtual User User { get; set; }

    [InverseProperty("Order")]
    public virtual ICollection<Item> Items { get; set; }        
}

public class MyCart
{
    [Key, ForeignKey("User")]
    public int UserId { get; set; }
    public virtual User User { get; set; }
}

public class User
{
    public int Id { get; set; }
    public int CreditCard { get; set; }
    public string Country { get; set; }
    public int CCExpMonth { get; set; }
    public int CCExpYear { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }

    [InverseProperty("User")]
    public virtual ICollection<Order> Orders { get; set; }

    public virtual MyCart Cart { get; set; }
}


protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    modelBuilder.Entity<MyCart>()
        .HasKey(e => e.UserId);

    modelBuilder.Entity<User>()
                .HasOptional(s => s.Cart) // Mark MyCart is optional for User
                .WithRequired(ad => ad.User); // Create inverse relationship

}

更新：

public class Item
{
    public int Id { get; set; }

    public virtual int OrderId { get; set; }

    [ForeignKey("OrderId")]
    **[InverseProperty("Items")]**
    public virtual Order Order { get; set; }
}