實體框架關係 - sql錯誤

Question

我有一個項目，我試圖實現（看似）簡單的購物車。以下是相關實體。我經常收到各種各樣的錯誤，而不是無法處理order_Id列名稱。所以我懷疑訂單和物品之間的關係出了問題，但我也認爲在方法上可能會有更大的缺失。任何意見，將不勝感激。

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

我更正像下面的實體：

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; } 
}