如何映射两个一对一关系 [英] How to map two One or Zero to One relationships

问题描述

我有三个实体，名称为SellinRequest，MortgageAndRent和Album。每个SellinRequest和MortgageAndRent可能都有一个专辑。

  public class SellingRequest 
 {
 public int Id {get;组; } 
 public Album Album {get;组; } 
} 
 
 public class MortgageAndRent 
 {
 public int Id {get;组; } 
 public Album Album {get;组; } 
} 
 
 public class Album 
 {
 public int Id {get;组; } 
 public SellingRequest SellingRequest {get;组; } 
 public int SellingRequestId {get;组; } 
 
 public MortgageAndRent MortgageAndRent {get;组; } 
 public int MortgageAndRentId {get;组; } 
 
 public List<照片>照片{get;组; } 
} 
  

这是我要实现的逻辑：

• （SellingRequest 1 .... 0-1相册）


• （MortgageAndRent 1 .... 0-1相册）

使用这些映射：

  public class SellingRequestMap：EntityTypeConfiguration< SellingRequest> 
 {
 public SellingRequestMap（）
 {
 this.ToTable（SellingRequest）; 
 this.HasKey（sR => sR.Id）; 
 
 //每个SellingRequest可能有一张专辑。 （SellingRequest 1 .... 0-1 Album）
 this.HasOptional（sR => sR.Album）.WithOptionalPrincipal（a => a.SellingRequest）.WillCascadeOnDelete（false）; 
} 
} 
 
 public RentAndMortgageMap（）
 {
 this.ToTable（MortgageAndRent）; 
 this.HasKey（mR => mR.Id）; 
 
 //每个MortgageAndRent可能有一张专辑。 （MortgageAndRent 1 .... 0-1 Album）
 this.HasOptional（sM => sM.Album）.WithOptionalPrincipal（a => a.MortgageAndRent）.WillCascadeOnDelete（false）; 
} 
  

但我无法得到结果。我不知道如何将这两张表与Album表相关联。

解决方案

这是我将如何做诡异的语法。请注意新的 id 字段，并将相册属性标记为

  public class SellingRequest 
 {
 public int Id {get;组; } 
 public int AlbumId {get; set;} 
 
 public virtual Album Album {get;组; } 
} 
 
 public class MortgageAndRent 
 {
 public int Id {get;组; } 
 public int AlbumId {get; set;} 
 
 public virtual Album Album {get;组; } 
} 
 
 public class Album 
 {
 public int Id {get;组; } 
 
 public int SellingRequestId {get;组; } 
 public int MortgageAndRentId {get;组; } 
 
 public virtual SellingRequest SellingRequest {get;组; } 
 public virtual MortgageAndRent MortgageAndRent {get;组; } 
 
 public virtual List< Photo>照片{get;组; } 
} 
  

I have three entities with the name of SellinRequest, MortgageAndRent and Album. Each of SellinRequest and MortgageAndRent may have an Album.

public class SellingRequest
{
    public int Id { get; set; }
    public Album Album { get; set; }  
}

public class MortgageAndRent
{
    public int Id { get; set; } 
    public Album Album { get; set; }
}

public class Album
{
    public int Id { get; set; }
    public SellingRequest SellingRequest { get; set; }
    public int SellingRequestId { get; set; }

    public MortgageAndRent MortgageAndRent { get; set; }
    public int MortgageAndRentId { get; set; }

    public List<Photo> Photos { get; set; }
}

This is the logic I want to be implemented:

• (SellingRequest 1 .... 0-1 Album)
• (MortgageAndRent 1 .... 0-1 Album)

With these mappings:

public class SellingRequestMap : EntityTypeConfiguration<SellingRequest>
{
    public SellingRequestMap()
    {
        this.ToTable("SellingRequest");
        this.HasKey(sR => sR.Id);

        // Each SellingRequest may have one Album. (SellingRequest 1 .... 0-1 Album)
        this.HasOptional(sR => sR.Album).WithOptionalPrincipal(a => a.SellingRequest).WillCascadeOnDelete(false);
    }
}

public RentAndMortgageMap()
    {
        this.ToTable("MortgageAndRent");
        this.HasKey(mR=>mR.Id);

        // Each MortgageAndRent may have one Album. (MortgageAndRent 1 .... 0-1 Album)
        this.HasOptional(sM => sM.Album).WithOptionalPrincipal(a => a.MortgageAndRent).WillCascadeOnDelete(false);
    }

But I couldn't get the result. I don't know how to relate these two tables to Album table!

解决方案

Here is how I would do it w/o the fleunt syntax. Note the new id fields and that I marked the album properties as virtual

public class SellingRequest
{
    public int Id { get; set; }
    public int AlbumId {get;set;}

    public virtual Album Album { get; set; }  
}

public class MortgageAndRent
{
    public int Id { get; set; } 
    public int AlbumId {get;set;}

    public virtual Album Album { get; set; }
}

public class Album
{
    public int Id { get; set; }

    public int SellingRequestId { get; set; }   
    public int MortgageAndRentId { get; set; }

    public virtual SellingRequest SellingRequest { get; set; }
    public virtual MortgageAndRent MortgageAndRent { get; set; }

    public virtual List<Photo> Photos { get; set; }
}

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