Entity Framework 4 ctp5 一张表有同一个表的两个外键

Question

我有两个表：

用户和新闻。表 News 具有列 id、name、createdby、modifiedby。表 user 有列 id 和 name。表News 通过外键createdby 和modifiedby 引用表User。我用 实体框架 4 CTP5。我尝试访问创建者或修改者属性，但出现错误：无效的列名称“UserId1”，无效的列名称“UserId2”。有人可以解释我做错了什么吗？

public class News
{
    // Primitive properties

    public int ID { get; set; }
    public string Name { get; set; }
    public System.Guid UserId { get; set; }
    public System.Guid UserId1 { get; set; }

    // Navigation properties

    public virtual User User { get; set; }
    public virtual User User1 { get; set; }

}

public class User
{
    public int ID { get; set; }
    public string Name { get; set; }
}

public partial class SomeEntities : DbContext
{
    public SomeEntities() : base("name=SomeEntities"){ }

    public DbSet<User> Users { get; set; }
    public DbSet<News> News { get; set; }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<News>().Property(i => i.UserId).HasColumnName("CreatedBy");
        modelBuilder.Entity<News>().Property(i => i.UserId1).HasColumnName("ModifiedBy");
    }
}

Answer 1

以下对象模型为您提供了所需的结果（我重命名属性只是为了使其更具可读性）：

public class News
{
    public int ID { get; set; }
    public string Name { get; set; }
    public Guid CreatedBy { get; set; }
    public Guid ModifiedBy { get; set; }
    public virtual User CreatedByUser { get; set; }
    public virtual User ModifiedByUser { get; set; }
}

public class User
{
    public Guid ID { get; set; }
    public string Name { get; set; }
}

public class Ctp5Context : DbContext
{
    public DbSet<User> Users { get; set; }
    public DbSet<News> News { get; set; }
    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<News>()
                    .HasRequired(n => n.CreatedByUser)
                    .WithMany()
                    .HasForeignKey(n => n.CreatedBy);

        modelBuilder.Entity<News>()
                    .HasRequired(n => n.ModifiedByUser)
                    .WithMany()
                    .HasForeignKey(n => n.ModifiedBy)
                    .WillCascadeOnDelete(false);                        
    }
}