实体框架外键为主要关键代码 [英] Entity Framework Foreign Key as Primary Key Code First

问题描述

我有两个代码第一个模型，Foo和FooState，其中Foo有一个可选的FooState。

  public class Foo 
 {
 [Key] 
 public int FooId {get;组; } 
 
 public FooState FooState {get;组; 
} 
 
 public class FooState 
 {
 [Key] 
 public int FooStateId {get;组; 
 
 [必需] 
 public int State {get;组; } 
 
 [必需] 
 public Foo Foo {get;组; } 
} 
  

这样工作正常，但是当我尝试将外键添加到FooState时所以

  public class FooState 
 {
 [Key] 
 public int FooStateId {get;组; 
 
 [必需] 
 public int State {get;组; } 
 
 [ForeignKey（Foo）] 
 [必需] 
 public int FooId 
 public Foo Foo {get;组; 
} 
  

这一切都归结为因为FooStateId真的使用FooId作为主键。这从数据库的角度来看是有意义的。

然而，当保存FooState记录但仍保留必需属性时，我不需要填充Foo的实例。

这将允许我发送一个FooId和状态在一个dto，而不必从数据库中检索整个Foo对象，如果我想改变它的

我应该如何使用EF代码进行设置？

解决方案

  public class FooState 
 { 
 [必需] 
 [Key] 
 [ForeignKey（Foo）] 
 public int FooStateId {get;组; 
 
 [必需] 
 public int State {get;组; } 
 
 public Foo Foo {get;组; } 
} 
  

I have two code first models, Foo and FooState where Foo has an optional FooState.

public class Foo
{
    [Key]
    public int FooId { get; set; }

    public FooState FooState { get; set; }
}

public class FooState
{
    [Key]
    public int FooStateId { get; set; }

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

    [Required]
    public Foo Foo { get; set; }
}

This works fine however when I try to add the foreign key to FooState like so

public class FooState
{
    [Key]
    public int FooStateId { get; set; }

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

    [ForeignKey("Foo")]
    [Required]
    public int FooId
    public Foo Foo { get; set; }
}

It all falls over because FooStateId is really using FooId as it's primary key. This makes sense from a database point of view.

I would however like not to have to populate an instance of Foo when saving the FooState record but still retain the required attribute.

This would allow me to send down a FooId and state in a dto and not have to retrieve the whole Foo object from the DB if I want to make a change to its state.

How should I be setting this up with EF code first?

解决方案

I thought I'd give this a shot and it worked nicely.

public class FooState
{
    [Required]
    [Key]
    [ForeignKey("Foo")]
    public int FooStateId { get; set; }

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

    public Foo Foo { get; set; }
}

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