Question

我的 DbContext 中有用户实体。我想要的是用户应该能够为彼此提供参考/发表评论，因此我创建了参考实体。

public class Reference
{
    public virtual User By { get; set; } // user who leaves a reference

    public virtual User To { get; set; } // user who has given a reference

    public string Opinions { get; set; }
}

用户实体

中的

public virtual ICollection<Reference> ReferencedTo { get; set; } // collection of references that user has given

public virtual ICollection<Reference> ReferencedBy { get; set; } // collection of references that user has been given

我应该怎么做才能使它与DataAnnonations或FluentAPI一起使用，或者您将如何解决这个问题并解决？

Answer 1

你需要做这样的事情：

public class Reference
{
    public int ReferenceId { get; set; }

    public int ByUserId { get; set; }

    public virtual User By { get; set; } // user who leaves a reference

    public int ToUserId { get; set; }

    public virtual User To { get; set; } // user who has given a reference

    public string Opinions { get; set; }
}

public class User
{
    public int UserId { get; set; }

    public string Name { get; set; }

    public virtual ICollection<Reference> ReferencedTo { get; set; } // collection of references that user has given

    public virtual ICollection<Reference> ReferencedBy { get; set; } // collection of references that user has been given
}

public class MyContext : DbContext
{
    public DbSet<User> Users { get; set; }
    public DbSet<Reference> References { get; set; }

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        modelBuilder.Entity<Reference>()
            .HasRequired(x => x.By)
            .WithMany(x => x.ReferencedBy)
            .HasForeignKey(x => x.ByUserId)
            .WillCascadeOnDelete(false);

        modelBuilder.Entity<Reference>()
            .HasRequired(x => x.To)
            .WithMany(x => x.ReferencedTo)
            .HasForeignKey(x => x.ToUserId)
            .WillCascadeOnDelete(false);
    }
}

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