Enity框架外鍵

我有三個enitiesEnity框架外鍵

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;} 
}

在上述交易表

有兩個ID商家ID和用戶ID，我想這對客戶和商戶的外鍵表，請解釋我如何添加外鍵約束我經歷了很多例子，但無法得到這個答案

d另一個疑問是，如果我添加客戶類型內幕交易表將我能夠在實體框架

我試圖通過follwing代碼

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

我越來越添加約束獲取的事務表客戶的詳細資料異常如下

其他資料：類型「Dutch.Models.Transaction」的ForeignKeyAttribute物業「客戶」無效。在依賴類型 'Dutch.Models.Transaction'上找不到'外部關鍵字' 'Customerid'。名稱值應該是以逗號分隔的外鍵屬性名稱列表。

來源

2015-11-18 Pragadees

在EF6中，據我所知，1對1關係將使用約定PK = FK，所以你有FK約束，但是ese會考慮Id的。如果您在交易中添加了客戶類型，只要您懶惰地/明確地加載它們，您就可以獲取詳細信息。 – DevilSuichiro

你能解釋一下，我仍然不能理解 – Pragadees

這可能有所幫助：http：//stackoverflow.com/questions/15483019/entity-framework-code-first-how-to-annotate-a-foreign-key-for-a- default-valu –

我終於做到由外鍵約束我的模型看起來像現在這樣

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; } 
}

那麼客戶和商家都會有交易

的收集和交易表

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;} 
}

來源

2015-11-18 16:49:35 Pragadees

回答

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