功能NHibernate automappings与自我参照 | automappings与自我参照

本文介绍了功能NHibernate automappings与自我参照的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

我有一个简单的类，看起来像这样...

I have a simple class that looks like this...

public class Item {
    public virtual int Id { get; set; }
    public virtual string Name { get; set; }
    public virtual int ParentId { get; set; }

    public virtual IList<Item> Children { get; private set; }

    public Item() {
        Children = new List<Item>();
    }
}

...其中ID是主键和的ParentId是外键。当我运行这段代码，我得到无效的对象名称ItemToItem。例外，我想不出有什么不对？我好像NHibernate的尝试从表中选择名为ItemToItem或类似的东西？

... where the Id is the primary key and ParentId is the foreign key. When I run this code I get Invalid object name 'ItemToItem'. exception and I can't figure out what's wrong? I seems like NHibernate tries to select from a table called ItemToItem or something like that?

推荐答案

正确的方式自我引用

// Class
public class Item
{
    public virtual int Id { get; set; }
    public virtual string Name { get; set; }
    public virtual Item Parent { get; private set; }
    public virtual IList<Item> Children { get; set; }
    public Item() {
        Children = new List<Item>();
    }
 }

 // Map
 References(x => x.Parent).Column("ParentId");
 HasMany(x => x.Children).Cascade.All().KeyColumn("ParentId");

 // Add Item
 session.Save(new Item { Description = "Electronics",
                        Children = {
                                new Item { Description = "PS2" },
                                new Item { Description = "XBox" }
                        }});
// Get Item
var items =
          (from c in session.Linq<Item>()
                 where c.Parent == null
                 select c).ToList();

这篇关于功能NHibernate automappings与自我参照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！