1
我很新的NHibernate。通过代码NHibernate映射 - 多对多 - 双向导航
我有许多映射工作。他们是这样的:
public abstract class EntityMapping<T> : ClassMapping<T> where T : Entity
{
public EntityMapping()
{
Id(x => x.Id, map => map.Generator(new IdentityGeneratorDef()));
}
}
public class PersonMapping : EntityMapping<Person>
{
public PersonMapping()
{
Property(x => x.Name);
}
}
public class ParentMapping : JoinedSubclassMapping<Parent>
{
public ParentMapping()
{
Property(x => x.ParentOf);
Key(x => x.Column("ParentId"));
Bag(x => x.Children, map =>
{
map.Cascade(Cascade.All);
map.Table("ParentChildren");
map.Key(x => x.Column("ParentId"));
},
r => r.ManyToMany(rm => rm.Column("ChildId")));
}
}
public class ChildMapping : JoinedSubclassMapping<Child>
{
public ChildMapping()
{
Property(x => x.Toys);
Key(x => x.Column("ChildId"));
Bag(x => x.Parents, map =>
{
map.Cascade(Cascade.All);
map.Table("ParentChildren");
map.Inverse(true);
map.Key(x => x.Column("ChildId"));
},
r=>r.ManyToMany(rm => rm.Column("ParentId")));
}
}
当我做
var parent = session.Get<Parent>(1);
parent.Children.First(); // Works
我可以访问已添加的孩子。但是,当我尝试导航时,即:
var child = session.Get<Child>(2);
child.Parents.First(); // Doesn't work.
子对象上的父集合是空的。
有人能够解释这个问题吗?
干杯,
詹姆斯
编辑
对不起,我用下面的代码保存并让我的实体:
using(var session = _sessionFactory.OpenSession())
{
using(var transaction = session.BeginTransaction())
{
var person = new Parent(){Name = "James", ParentOf = 1};
var child = new Child(){ Name="James Jr." Toys = 20 };
person.Children.Add(child);
session.Save(person);
transaction.Commit();
}
}
检索数据:
using(var session = _sessionFactory.OpenSession())
{
using(var transaction = session.BeginTransaction())
{
var james = session.Get<Parent>(1);
var child = session.Get<Child>(2);
transaction.Commit();
}
}
我是否需要在交易中包装get?
干杯,
詹姆斯
向我们展示用于保存和读取关系以及会话/事务边界的完整代码。 – NOtherDev 2012-03-23 17:19:23