Question

我的解决方案中有以下模型：

internal class Customer
{
    [Key]
    public int CustomerId { get; set; }

    [MaxLength(50)]
    public string FirstName { get; set; }

    [MaxLength(50)]
    public string LastName { get; set; }

    [MaxLength(12)]
    public string PhoneNumber { get; set; }
}

internal class Product
{
    [Key]
    public int ProductId { get; set; }

    [MaxLength(100)]
    public string ProductName { get; set; }

    public decimal Price { get; set; }

    public double ProductWeight { get; set; }

    public bool InStock { get; set; }

}

internal class Order
{
    [Key]
    public int OrderId { get; set; }

    [ForeignKey("Customer")]
    public int CustomerId { get; set; }
    public Customer Customer { get; set; }

    public DateTime OrderDate { get; set; }

    [MaxLength(30)]
    public string PoNumber { get; set; }
}

class Cart
{
    public virtual ICollection<Order> Orders { get; set; }

    public virtual ICollection<Product> Products { get; set; }

    public uint Quantity { get; set; }
}

...和DB上下文

class Store : DbContext
{
    public DbSet<Customer> Customers { get; set; }
    public DbSet<Product> Products { get; set; }
    public DbSet<Order> Orders { get; set; }
    public DbSet<Cart> Carts { get; set; }

}

当我调试时，会抛出一个异常，说“'Carts'基于没有定义键的'Cart'类型”。我从DB上下文中删除了Cart类，解决方案运行正常。我尝试了几种不同的方法来声明Cart类中的键，包括：

[ForeignKey("Order")]
[Column(Order = 1)]
public int OrderId { get; set; }
public Order Order { get; set; }


[ForeignKey("Product")]
[Column(Order = 2)]
public int ProductId { get; set; }
public Product Product { get; set; }

或

[Key]
public int OrderId { get; set; }

[Key]
public int ProductId { get; set; }

我可能会出错的任何想法？（请记住这是一个教育项目，因此不需要对数据库设计的反馈）

似乎无法在代码优先实体框架中正确定义复合外键

0 个答案: