如何级联保存在NHibernate的CompositeId？ [英] How to cascade Save with CompositeId in NHibernate?

问题描述

  A（id，Name）$ b我有一个简单的三表格DB与多对多的关系。 $ b B（id，Name）
 AB（AId，BId）引用A和B 
  

相应的类：

  public class A 
 {
 public virtual int Id {get;组; } 
 public virtual string Name {get;组; } 
} 
 
 public class B 
 {
 public virtual int Id {get;组; } 
 public virtual string Name {get;组; } 
} 
 
 public class AB 
 {
 public virtual A A {get;组; } 
 public virtual B B {get;组; } 
 public override bool Equals（object obj）{/ * routine * /} 
 public override int GetHashCode（）{/ * routine * /} 
} 
  
 
我已经与Fluent NHibernate进行了映射：
 
 $ $ p $ code> public class AMap：ClassMap< A> 
 {
 public AMap（）
 {
 Id（x => x.Id）.GeneratedBy.Identity（）; 
 Map（x => x.Name）; 
} 
} 
 
 public class BMap：ClassMap< B> {/ *与A * /}相同
 
公共类ABMap：ClassMap< AB> 
 {
 public ABMap（）
 {
 CompositeId（）
 .KeyReference（x => xA，AId）
 .KeyReference（x => xB，BId）; 
 
 
 
 
 
 
 $ b所以现在我想能够做一些像这
  var a = new A {Name =a1}; 
 var b = new B {Name =b1}; 
 var ab = new AB {A = a，B = b}; 
 
 //session.SaveOrUpdate(a）; 
 //session.SaveOrUpdate（b）; 
 session.SaveOrUpdate（ab）; 
  
但在 SaveOrUpdate 上我得到 TransientObjectException  。所以要传递它，我需要保存AB之前保存更新 A和B.但似乎应该有另一种方法来将这些对象保存在一个单独的SaveOrUpdate中。
 
 
是否有任何方法指向AB映射到级联 A和B上保存操作？
 
 
 
 更新： 
 
 
 
为了清楚起见，我删除了A类中的AB链接列表。原来是：
 
 
  public class A 
 {
 public A（）
 {
 LinkToB = new List< AB>（）; 
} 
 
 public virtual int Id {get;组; } 
 public virtual string Name {get; set} 
公共虚拟IList< AB> LinkToB {get;私人设置} 
} 
 
公共类AMap：ClassMap< A> 
 {
 public AMap（）
 {
 Id（x => x.Id）.GeneratedBy.Identity（）; 
 Map（x => x.Name）; 
 
 HasMany（x => x.LinkToB）
 .KeyColumn（AId）
 .Inverse（）
 .Cascade.All（）
 .AsBag（）; 
 
 
 
 //在交易中
 var a = new A {Name =a1}; 
 var b = new B {Name =b1}; 
 
 a.LinkToB.Add（new AB {A = a，B = b}）; 
 // session.SaveOrUpdate（b）; 
 session.SaveOrUpdate（a）; 
  
谢谢！ 
 
解决方案
我在nhibernate用户组中问过这个问题。答案是，没有办法使用composite-id级联任何操作（也许在将来的版本中可能）。
 
 
所以我做了一个解决方法。我放置了两个引用（与级联多对一）而不是CompositeId，并将Id添加到AB表和AB实体。现在它正在工作，A和B实体级联。
 
I have a simple three table DB with many-to-many relation.
A(id, Name)
B(id, Name)
AB(AId, BId) references A and B
The corresponding classes:
public class A
{
    public virtual int Id { get; set; }
    public virtual string Name { get; set; }
}

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

public class AB
{
    public virtual A A { get; set; }
    public virtual B B { get; set; }
    public override bool Equals(object obj) { /* routine */ }
    public override int GetHashCode() { /* routine */ }
}
I have made mappings with Fluent NHibernate:
public class AMap : ClassMap<A>
{
    public AMap()
    {
        Id(x => x.Id).GeneratedBy.Identity();
        Map(x => x.Name);
    }
}

public class BMap : ClassMap<B> { /* The same as for A */ }

public class ABMap : ClassMap<AB>
{
    public ABMap()
    {
        CompositeId()
            .KeyReference(x => x.A, "AId")
            .KeyReference(x => x.B, "BId");
    }
}
So now I want to be able to do something like this
var a = new A { Name = "a1" };    
var b = new B { Name = "b1" };    
var ab = new AB { A = a, B = b };

//session.SaveOrUpdate(a);
//session.SaveOrUpdate(b);
session.SaveOrUpdate(ab);
But on SaveOrUpdate I do get TransientObjectException. So to pass over it I need to SaveOrUpdate A and B before saving the AB. But it seems that there should be the other way to persist these objects in a single SaveOrUpdate.

Is there any way to point in AB mapping to Cascade A and B on save operation?

UPDATE:

I removed the List of AB links in A class for clarity. Originally it was:
public class A
{
    public A()
    {
        LinkToB = new List<AB>();
    }

    public virtual int Id { get; set; }
    public virtual string Name { get; set }
    public virtual IList<AB> LinkToB { get; private set; }
}

public class AMap : ClassMap<A>
{
    public AMap()
    {
        Id(x => x.Id).GeneratedBy.Identity();
        Map(x => x.Name);

        HasMany(x => x.LinkToB)
            .KeyColumn("AId")
            .Inverse()
            .Cascade.All()
            .AsBag();
    }
}

// inside the transaction
var a = new A { Name = "a1" };
var b = new B { Name = "b1" };

a.LinkToB.Add(new AB { A = a, B = b });
// session.SaveOrUpdate(b);
session.SaveOrUpdate(a);
Thank you!
解决方案
I did ask this question at nhibernate user group. And the answer was that there is no way to cascade any operation using composite-id (maybe in the future releases it will be possible).

So I made a workaround. I placed two References (many-to-one with cascading) instead of CompositeId and added Id to the AB table and AB entity. Now it's working and A and B entities are cascading.

                        
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