Question

我正在尝试使用实体框架代码第一种方法创建1-n关系。以下是我的课程

public class User
{

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


    //public virtual Vote Vote { get; set; }
    [Required]
    public string Name { get; set; }
    [Required]
    public string Email { get; set; }
    [Required]
    public string Bio { get; set; }
    [Required]
    public string Education { get; set; }
    [Required]
    public string Experience { get; set; }

    public string Password { get; set; }

}

以下是我的第二堂课

public class Vote
{
    [Required]
    [Key]
    public int VoteID { get; set; }

    [ForeignKey("UserID")]
    [Required]
    public virtual User User { get; set; }

    //public virtual int UserID { get; set; }

    [Required]
    public int VoteCount { get; set; }
    [Required]

    public  int UserID { get; set; }


}

用户和投票和1-n关系，在我的情况下，我的意思是UserID应该是投票表中的外键。但是当我用以下命令创建db时

   enable-migrations -ContextTypeName ProfileOne.PO -Force

   Add-migration PO

   update-database

我没有得到任何外键OR列名UserID

任何帮助将不胜感激，为什么我无法取得成果。

Answer 1

尝试使用以下方法：

public class User
{
    [Key]
    public int UserID { get; set; }

    [Required]
    public string Name { get; set; }

    [Required]
    public string Email { get; set; }

    [Required]
    public string Bio { get; set; }

    [Required]
    public string Education { get; set; }

    [Required]
    public string Experience { get; set; }

    public string Password { get; set; }        


    //Navigation properties
    public virtual ICollection<Vote> Votes { get; set; }
}


public class Vote
{
    [Key]
    public int VoteID { get; set; } 

    [Required]
    public int VoteCount { get; set; }  


    //Foreign key for User
    [Required]
    public int UserID { get; set; } 

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

有关详细信息，请查看Entity Relationships。希望这会有所帮助...

Answer 2

修改您的课程如下：

public class User
{
    [Key]
    public int UserID { get; set; }

    [Required]
    public string Name { get; set; }

    [Required]
    public string Email { get; set; }

    [Required]
    public string Bio { get; set; }

    [Required]
    public string Education { get; set; }

    [Required]
    public string Experience { get; set; }

    public string Password { get; set; }

    public virtual Vote Vote { get; set; }
}

public class Vote
{
    [Required]
    [Key]
    public int VoteID { get; set; }

    [Required]
    public int VoteCount { get; set; }

    [Required]
    public  int UserID { get; set; }

    //[ForeignKey("UserID")]
    //[Required]
    public virtual User User { get; set; }
}

2个实体之间的关系由虚拟属性定义，您对它们进行了评论。

代码第一种方法不创建外键

2 个答案: