级联删除规则EF 4.1代码首先使用共享主键关联 [英] Cascade Delete Rule in EF 4.1 Code First when using Shared Primary Key Association

问题描述

我根据这个答案实施了双向1：1的关系：

。

解决方案

以下流畅的API代码完美地打开级联删除在数据库上：

  public class Student 
 {
 public virtual int StudentId {get;组; } 
 public virtual Anamnesis Anamnesis {get;组; 
} 
 
 public class Anamnesis 
 {
 public int AnamnesisId {get;组; } 
 public virtual Student Student {get;组; } 
} 
 
 public class上下文：DbContext 
 {
 public DbSet< Student>学生{get;组; } 
 public DbSet< Anamnesis>消失组; 
 
 protected override void OnModelCreating（DbModelBuilder modelBuilder）
 {
 modelBuilder.Entity< Student>（）
 .HasRequired（s => s.Anamnesis）
 .WithRequiredPrincipal（a => a.Student）
 .WillCascadeOnDelete（）; 
} 
} 
  

I implemented a bidirectional 1:1 relationship based on this answer:

Primary /Foreign Key in Entity Framework

I define the bidirectional relation this way:

public class Student
{   
    public virtual int StudentId { get; set; }
    public virtual Anamnesis Anamnesis { get; set; }

    . . .
}

public class Anamnesis
{
    [Key, ForeignKey("Student")]
    public int AnamnesisId { get; set; }

    public virtual Student Student { get; set; }

    . . .
}

where, Student is the principal entity and Anamnesis it the entity that shares the PK.

Now I'd like that the relationship created had a Delete Rule = CASCADE. Actually, the relationship that is being created has Delete Rule = NO ACTION as seen in the following picture:

If I manually delete this relation inside the Table Properties window and add other relation with Delete Rule = CASCADE, the code works as I expect allowing me to delete a Student and it's shared Anamnesis that has the same ID.

So, here goes my question:

Is there a way of using Data Annotation (not Fluent API) in my class so that I get a Relation with CASCADE delete rule? I'd prefer using Data Annotation but if it's not possible, I'd be happy with some Fluent API code that makes this work.

NOTE

I have tried the Fluent API code that is shown in this post. It doesn't work in my case where I have bidirectional properties.

解决方案

The following fluent API code perfectly switch on the cascade delete on the database:

public class Student
{   
    public virtual int StudentId { get; set; }
    public virtual Anamnesis Anamnesis { get; set; }
}

public class Anamnesis
{        
    public int AnamnesisId { get; set; }
    public virtual Student Student { get; set; }
}

public class Context : DbContext
{
    public DbSet<Student> Students { get; set; }
    public DbSet<Anamnesis> Anamnesises { get; set; }

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        modelBuilder.Entity<Student>()
                    .HasRequired(s => s.Anamnesis)
                    .WithRequiredPrincipal(a => a.Student)
                    .WillCascadeOnDelete();
    }
}

这篇关于级联删除规则EF 4.1代码首先使用共享主键关联的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！