实体框架6多表到一个外键关系代码第一 [英] Entity Framework 6 multiple table to one foreign key relationship code first

问题描述

我想知道有没有人可以告诉我如何在EF6中首先使用代码完成下面的代码。

如果将Table_3作为列表添加到Table_1& Table_2在我的实体。 EF自动为Table_3中的两个表生成一个外键列，而不是识别它们的类型相同。

我的模型类设置如下。

  public interface IParent 
 {
 int ID {get;组; } 
列表< Table_3>孩子{get;组; } 
} 
 
 public class Table_1：IParent 
 {
 [Key] 
 public int ID {get;组; } 
 public string Name {get;组; } 
 public virtual List< Table_3>孩子{get;组; 
} 
 
 public class Table_2：IParent 
 {
 [Key] 
 public int ID {get;组; } 
 public string Name {get;组; } 
 public virtual List< Table_3>孩子{get;组; 
} 
 
 public class Table_3 
 {
 [Key] 
 public int ID {get;组; } 
 public int ParentID {get;组; } 
 [ForeignKey（ParentID）] 
 public virtual IParent Parent {get;组; 
} 
  

EF代码首先生成以下

编辑

只是让有同样问题的人知道

我现在通过更改IParent来解决这个问题接口到抽象类
我的课程现在看起来像以下

  [Table（ParentBase）] 
 public abstract class ParentBase 
 {
 [Key] 
 public int ID {get;组; } 
 public List< Table_3>孩子{get;组; } 
} 
 [Table（Table_1）] 
 public class Table_1：ParentBase 
 {
 public string Name {get;组; 
} 
 [Table（Table_2）] 
 public class Table_2：ParentBase 
 {
 public string Name {get;组; } 
} 
 [表（Table_3）] 
 public class Table_3 
 {
 [Key] 
 public int ID {get;组; } 
 public int ParentID {get;组; } 
 [ForeignKey（ParentID）] 
 public virtual ParentBase Parent {get;组; 
} 
  

表格安排

这样做会很好，如果原来的话可能会更好一些。

解决方案

我也有这个问题，从开始就使用抽象类而不是接口。
我的问题是我的table_3有两个导航属性：
一个是公共虚拟Table_1，另一个是公共虚拟Table_2，然后EF只是提供了这些额外的外键列
我合并了两个导航属性一个到
public virtual parentbase {get; set;}。然后它工作。希望这有帮助。

侧面注意，建议在public List中添加虚拟关键字List Children {get;组; }在parentbase类中，因为在以前的例子中，它已经是这样了。谢谢你发布这个，我也遇到这个问题。

I am wondering if anyone could advise me on how to accomplish the below using code first in EF6

If I add the Table_3 as a List on to Table_1 & Table_2 in my entities. EF automatically generates a foreign key column for both tables in Table_3 instead of recognizing that they are of the same type.

My model classes are set as follows.

public interface IParent
{
    int ID { get; set; }
    List<Table_3> Children { get; set; }
}

public class Table_1 : IParent
{
    [Key]
    public int ID { get; set; }
    public string Name { get; set; }
    public virtual List<Table_3> Children { get; set; }
}

public class Table_2 : IParent
{
    [Key]
    public int ID { get; set; }
    public string Name { get; set; }
    public virtual List<Table_3> Children { get; set; }
}

public class Table_3
{
    [Key]
    public int ID { get; set; }
    public int ParentID { get; set; }
    [ForeignKey("ParentID")]
    public virtual IParent Parent { get; set; }
}

EF code first generates the below

Edit

Just to let anyone having the same problems know

I have now resolved this by changing the IParent interface to an abstract class my classes now look like the following

[Table("ParentBase")]
public abstract class ParentBase
{
    [Key]
    public int ID { get; set; }
    public List<Table_3> Children { get; set; }
}
[Table("Table_1")]
public class Table_1 : ParentBase
{
    public string Name { get; set; }
}
[Table("Table_2")]
public class Table_2 : ParentBase
{
    public string Name { get; set; }
}
[Table("Table_3")]
public class Table_3
{
    [Key]
    public int ID { get; set; }
    public int ParentID { get; set; }
    [ForeignKey("ParentID")]
    public virtual ParentBase Parent { get; set; }
}

with a table arrangement of

this will work although it would have been nicer if the original could have been met.

解决方案

I had this problem too, and I used abstract class instead of interface from the beginning. The problem for mine was my table_3 have two navigation properties: one is public virtual Table_1, another is public virtual Table_2, and then EF just provisioned these extra foreign key columns, I merged the two navigation properties into one to public virtual parentbase {get;set;}. And then it worked. Hope this helps.

Side Note,Would suggest to add virtual keyword on public List Children { get; set; } in parentbase class, because in your previous example , it was already like that.

Thanks for posting this, i came across this issue too.

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