Enity Framework外键

Question

我有三个恩赐

public class Customer
{

    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    [Key]
    public int Customerid { get; set; }
    public string Name { get; set; }
    public string email { get; set; }
    public string Phoneno { get; set; }
}

和第二次Enitity

public class Merchant
{
    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int Merchantid { get; set; }
    [Required]
    [RegularExpression("^[\\p{L} .-]+$", ErrorMessage = "Use letters only please")]
    public string MerchantName { get; set; }
    [Required]
    [RegularExpression("^[\\p{L} .-]+$", ErrorMessage = "Use letters only please")]
    public string BusinessName { get; set; }
    [Required]
    public string OfficePhno { get; set; }
}

public class Transaction
{
    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int TransactionId { get; set; }
    public int Merchantid {get; set;}
    public int Customerid {get; set;}
    public int Amount { get; set; }
    public Customer customer {get; set;}
    public Merchant merchant {get; set;}
}

在上面的交易表中有两个ID商家ID和客户ID我希望这是客户和商家表的外键， 请解释我如何添加外键约束我经历了很多例子，但是没能得到答案

另一个疑问是，如果我在Transaction表中添加Customer类型，我能否在Entity的事务表中获取customer的详细信息 框架

我试图通过以下代码添加Constraint

[ForeignKey("Customerid")] 
pubic virtual Customer customer {get; set;}

我得到如下例外

  

其他信息：属性'Customer'上的ForeignKeyAttribute   类型'Dutch.Models.Transaction'无效。外键名称   在依赖类型上找不到“Customerid”   'Dutch.Models.Transaction'。 Name值应以逗号分隔   外键属性名称列表。

Answer 1

我终于通过Foreignkey约束了 我的模型现在看起来像这样

public class Customer
{
   [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
   [Key]
   public int Customerid { get; set; }
   public string Name { get; set; }
   public string email { get; set; }
   public string Phoneno { get; set; }
   public ICollection<Transaction> Transactions { get; set; }
}

public class Merchant
{
   [Key]
   [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
   public int Merchantid { get; set; }
   [Required]
   [RegularExpression("^[\\p{L} .-]+$", ErrorMessage = "Use letters only     please")]
   public string MerchantName { get; set; }
   [Required]
   [RegularExpression("^[\\p{L} .-]+$", ErrorMessage = "Use letters only please")]
   public string BusinessName { get; set; }
   [Required]
   public string OfficePhno { get; set; }
   public ICollection<Transaction> Transactions { get; set; }
}

因此，客户和商家将拥有一系列交易

并在交易表中

public class Transaction
{
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public int TransactionId { get; set; }
public int Merchantid {get; set;}
public int Customerid {get; set;}
public int Amount { get; set; }
[ForeignKey("Customerid")]
public Customer customer {get; set;}
[ForeignKey("Merchantid")]
public Merchant merchant {get; set;}
}