流利的nhibernate一对多

Question

我有一对多的关系,不能让级联工作,一旦我设置级联我只是得到"对象引用一个未保存的瞬态实例......".

我的映射看起来像这样

public class SharedDetailsMapping : ClassMap<SharedDetails>
{
    public SharedDetailsMapping()
    {
        Id(x => x.Id).GeneratedBy.Identity();
        HasMany(x => x.Foos);
    }
}

public class FooMapping : ClassMap<Foo>
{
    public FooMapping()
    {
        Id(x => x.Id).GeneratedBy.Identity();
        References(x => x.SharedDetails).Cascade.SaveUpdate();
    }
}

这样的课程

public class Foo
{
    public Foo()
    {
        SharedDetails = new SharedDetails();
        SharedDetails.Foos.Add(this);
    }

    public Foo(SharedDetails sharedDetails)
    {
        SharedDetails = sharedDetails;
        SharedDetails.Foos.Add(this);
    }

    public virtual Guid Id { get; set; }
    public virtual SharedDetails SharedDetails { get; set; }
}

public class SharedDetails
{
    public SharedDetails()
    {
        Foos = new List<Foo>();
    }

    public virtual Guid Id { get; set; }
    public virtual IList<Foo> Foos { get; set; }
}

然后我想创建Foos而不必首先保存SharedDetails,如果它是一个新的Foo,就像这样:

using (var transaction = _session.BeginTransaction())
{
    var shared = new SharedDetails();

    var fooOne = new Foo(shared);
    _session.SaveOrUpdate(fooOne);

    var fooTwo = new Foo(shared);
    _session.SaveOrUpdate(fooTwo);

    transaction.Commit();
}

无法弄清楚我做错了什么,如果我首先保存SharedDetails,它的工作原理很糟糕,但这就是为什么我有Cascade设置.

Answer 1

在您的SharedDetailsMapping修改HasMany中添加.Inverse():

public class SharedDetailsMapping : ClassMap<SharedDetails>
{
    public SharedDetailsMapping()
    {
        Id(x => x.Id).GeneratedBy.Identity();
        HasMany(x => x.Foos)
           .Inverse();
    }
}

这指示Foo拥有该关系的NHibernate ,这将帮助它以正确的顺序保存关系中的对象(在这种情况下,SharedDetails必须首先保存,以便在Foo保存时保存其ID ).

关于目的/何时使用Inverse的进一步信息:NHibernate的逆 - 它的真正含义是什么？

TL; DNR版本:

如果您的类中有双向关系(一方是HasMany,另一方是References),那么HasMany应该有.Inverse().