如何实现一到一个代码第一种方法，如果我们有自动生成的ID

Question

我有这两个实体：

public class User 
{  
    [Key] 
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)] 
    public Guid Id { get; set; } 

    public string IdsrvUniqueId { get; set; } 

    public string FirstName { get; set; } 
    public string LastName { get; set; } 
    public string Email { get; set; } 

    public string About { get; set; } 
    public GenderEnum Gender { get; set; } 

    public DateTime BirthDate { get; set; } 
    public string PhoneNumber { get; set; } 
} 


public class NotificationSetting 
{  
    [Key] 
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)] 
    public Guid Id { get; set; } 

    public bool AutomaticallySubscribeToAllGroups { get; set; } 

    public bool AutomaticallySubscribeToAllGroupsWithTag { get; set; } 
} 

我想要做的是implemente 1：他们之间，但目前与1间的关系没有成功。我试图用数据符号和装饰他们看起来像这样：

public class User 
    {  
     [Key] 
     [DatabaseGenerated(DatabaseGeneratedOption.Identity)] 
     public Guid Id { get; set; } 

     .......... 

     // Navigation properties 
     public virtual NotificationSetting NotificationSettings { get; set; } 
    } 

public class NotificationSetting 
    {  
     [Key] 
     [DatabaseGenerated(DatabaseGeneratedOption.Identity)] 
     [ForeignKey("User")] 
     public Guid Id { get; set; } 

     .... 

     // Navigation properties 
     public virtual User User { get; set; } 
    } 

它编译，生成迁移文件，但是当我尝试添加新的用户，我得到一个错误。 你能告诉我这里有什么问题吗？我怎样才能实现我的目标。

Answer 1

我认为ForeignKey属性是在错误的属性上。

public class User 
{  
    [Key] 
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)] 
    public Guid Id { get; set; } 

    .......... 

    // Navigation properties 
    public virtual NotificationSetting NotificationSettings { get; set; } 
} 

public class NotificationSetting 
{  
    [Key] 
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)] 
    public Guid Id { get; set; } 

    .... 
    [ForeignKey("User")] 
    public Guid UserId { get; set; } 
    // Navigation properties   
    public virtual User User { get; set; } 
} 

这就是我总是定义它们的方法。您发布它的方式，它使用NotificationSetting的PK作为用户的FK

Answer 2

当您将实体配置为具有一对一关系时，您的从属实体中的密钥（NotificationSetting）是主体实体的外键（User）也一样，所以它不能自动生成数据库字段，所以在NotificationSetting的[DatabaseGenerated(DatabaseGeneratedOption.Identity)]应删除：

public class User 
{  
    [Key] 
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)] 
    public Guid Id { get; set; } 

    .......... 

    // Navigation properties 
    public virtual NotificationSetting NotificationSettings { get; set; } 
} 

public class NotificationSetting 
{  
    [Key] 
    [ForeignKey("User")] 
    public Guid Id { get; set; } 

    .... 

    // Navigation properties 
    public virtual User User { get; set; } 
}