使用ICriterion过滤NHibernate子类型

Question

有没有什么办法可以在我通过向执行的DetachedCriteria添加ICriterion来点击数据库之前在SubType字段上过滤我的NHibernate查询？

我的代码看起来像这样:

DetachedCriteria detachedCriteria = DetachedCriteria.For(typeof(MyObject));

    ProjectionList projectionList = Projections.ProjectionList();
    projectionList.Add(Projections.SqlProjection("{alias}.SubType as SubType", new string[] { "SubType" }, new IType[] { TypeFactory.GetAnsiStringType(15) }));

    dc.SetProjection(projectionList);
    dc.Add(Expression.Eq("SubType", "MYOBJECT"));

    using(ISession session = ...)

    {

       ICriteria criteria = detachedCriteria.GetExecutableCriteria(session);

    // Blows up because I don't know how to reference the SubType
    // field with an ICriterion (Expression.Eq("SubType", "MYOBJECT"))
       IList list = criteria.List();

    ...

    }

虽然这可能不是实现我的目标的正确方法,但我希望它至少是可能的,因为我不期待必须重构我期望/产生ICriterion的接口.我也不一定能够在我需要创建ICriterion对象的地方附近访问会话(但是我可以完全控制将使用的各种NHibernate字段/表的别名/命名).

Answer 1

进行了大量的谷歌搜索,找到了答案,这里是:http: //derek-says.blogspot.com/2008/08/excluding-particular-derived-types-in.html

   ICriteria crit = sess.CreateCriteria(typeof(Mammal));  
   crit.Add( Expression.Not( Expression.Eq("class", typeof(DomesticCat)) ) );  
   List mammals = crit.List();