EF4 code第一：如何添加关系不添加导航属性 [英] EF4 Code First: how to add a relationship without adding a navigation property

问题描述

我应该如何定义使用code第一，但不使用任何导航属性的关系？

How should I define relationships using Code First but without using any navigation properties?

previously我已经定义了一对多和多对多的在关系的两端使用导航属性。和相应的关系将在数据库中创建。这里的课程看起来怎么样（我已经转换了多对多的关系，一对多的简单）。

Previously I have defined One-Many and Many-Many by using navigation properties in both ends of the relationship. And the appropriate relationships are created in the database. here's a stripped down version of how the classes look like (I've converted the Many-Many relationships to one-many for simplicity).

public class User 
{
    public string UserId { get; set; }
    public string PasswordHash { get; set; }
    public bool IsDisabled { get; set; }
    public DateTime AccessExpiryDate { get; set; }
    public bool MustChangePassword { get; set; }

    public virtual Role Role { get; set; }
}

public class Role
{
    public int RoleId { get; set; }
    public string Name { get; set; }
    public string Description { get; set; }

    public virtual ICollection<User> Users { get; set; }
    public virtual ICollection<Right> Rights { get; set; }
}

public class Right
{
    public Guid RightId { get; set; }
    public string Name { get; set; }
    public string Description { get; set; }

    public virtual Role Role { get; set; }
}

不过，如果我删除了导航属性，正在创建无关系。这里的类会是什么样子。

However, if I remove the navigation properties, no relationships are being created. Here's how the classes would look like.

public class User 
{
    public string UserId { get; set; }
    public string PasswordHash { get; set; }
    public bool IsDisabled { get; set; }
    public DateTime AccessExpiryDate { get; set; }
    public bool MustChangePassword { get; set; }

    public int Role RoleId { get; set; }
}

public class Role
{
    public int RoleId { get; set; }
    public string Name { get; set; }
    public string Description { get; set; }
}

public class Right
{
    public Guid RightId { get; set; }
    public string Name { get; set; }
    public string Description { get; set; }

    public int RoleId { get; set; }
}

通知，而不是一个导航属性​​，我有相关的表的主键。一切都被在表上创建 - 除了关系。所以，我怎么这样做？

notice that instead of a navigation property, I have the primary key of the related table. Everything gets created on the table - except the relationship. So how do I get about doing this?

顺便说一句，我在的DbContext的OnModelCreating方法，但都无济于事尝试各种组合。任何帮助深表AP preciated！

BTW, I've tried various combinations in the OnModelCreating method of the dbcontext but to no avail. Any help is much appreciated!

谢谢，
梅尔

推荐答案

我相信你使用$ C $当c一总是需要在至少一方导航属性。然后，你就能够映射它：

I believe you always need navigation property on at least one side when using code-first. Then you will be able to map it:

public class User  
{     
    public string UserId { get; set; }     
    public string PasswordHash { get; set; }     
    public bool IsDisabled { get; set; }     
    public DateTime AccessExpiryDate { get; set; }     
    public bool MustChangePassword { get; set; }      
    public int RoleId { get; set; }
    public Role Role { get; set; }
}  

public class Role 
{     
    public int RoleId { get; set; }     
    public string Name { get; set; }     
    public string Description { get; set; } 
}  

public class Right 
{     
    public Guid RightId { get; set; }     
    public string Name { get; set; }     
    public string Description { get; set; }      
    public int RoleId { get; set; }
    public Role Role { get; set; }
} 

public class TestContext : DbContext
{
    public TestContext() : base("Entities")
    {}

    protected override void  OnModelCreating(System.Data.Entity.ModelConfiguration.ModelBuilder modelBuilder)
    {
        base.OnModelCreating(modelBuilder);

        modelBuilder.Entity<User>()
            .HasRequired(r => r.Role)
            .WithMany()
            .HasForeignKey(r => r.RoleId);

        modelBuilder.Entity<Right>()
            .HasRequired(r => r.Role)
            .WithMany()
            .HasForeignKey(r => r.RoleId);
    }
}

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