c# - nHibernate:无法解析属性

Question

我花了几个小时试图解决这个问题，包括在 StackOverflow 上浏览所有之前提出的问题。

我正在尝试通过 EvaluationHeadId 从 TrainingCourse 查询，这工作正常，但是，我尝试获取它返回的 TrainingRoute“无法解析属性:TrainingRoute.TrainingRouteDefinition of:Model.Entities.TrainingCourse”

它保存完美，我真正的问题是查询。

更新为:

            using (var session = SessionProvider.Instance.OpenSession())
            {
                using (var transaction = session.BeginTransaction())
                {
                    dto = session.QueryOver<TrainingCourse>()  
                            .JoinQueryOver<EvaluationHead>(p => p.EvaluationHeads)
                            .JoinQueryOver<TrainingRoute>(p => p.TrainingRoute)
                            .Where(c => c.EvaluationHeadID == headId)
                            .SelectList(l => l
                                .Select(h => h.TrainingCourseDefn).WithAlias(() => d.TrainingCourseDefn)
                                .Select(h => h.IsAvailable).WithAlias(() => d.IsAvailable)
                                .Select(h => h.TrainingRoute.TrainingRouteDefinition).WithAlias(() => d.TrainingRouteDefinition))
                            .TransformUsing(Transformers.AliasToBean<TrainingCourseDTO>())
                            .List<TrainingCourseDTO>();

                    transaction.Commit();           
                }
            }

映射:

        public TrainingCourseMap()
    {
        Id(x => x.TrainingCourseID).GeneratedBy.Identity();
        Map(x => x.TrainingCourseDefn);
        Map(x => x.IsAvailable);
        Map(x => x.TrainingCourseCreatedBy);
        Map(x => x.TrainingCourseDtCreation);
        Map(x => x.TrainingCourseDtModified);
        Map(x => x.TrainingCourseModifiedBy);

        References(x => x.TrainingRoute).Column("TrainingRouteID").Cascade.None();
        HasManyToMany(x => x.EvaluationHeads).Table("EvaluationTraining").ParentKeyColumn("TrainingCourseID").ChildKeyColumn("EvaluationHeadID").Inverse().Cascade.All();
    }

---

        public EvaluationHeadMap()
    {
        Id(x => x.EvaluationHeadID).GeneratedBy.Identity();
        Map(x => x.ManagerID);
        Map(x => x.SupervisorID);
        Map(x => x.EvaluationStartPeriod);
        Map(x => x.EvaluationEndPeriod);
        Map(x => x.EmployeeScalePoint);
        Map(x => x.KRASignature);
        Map(x => x.KRASignatureDate);
        Map(x => x.DateCreated);
        Map(x => x.DateModified);
        HasMany(x => x.KeyResultAreas).KeyColumn("EvaluationHeadID").Cascade.All().Inverse();
        HasMany(x => x.Evaluations).KeyColumn("EvaluationHeadID").Inverse().Cascade.All();

        HasManyToMany(x => x.TrainingCourses).Table("EvaluationTraining").ParentKeyColumn("EvaluationHeadID").ChildKeyColumn("TrainingCourseID").Cascade.All().AsBag();

        References(x => x.Stage).Column("StageID").Cascade.None();
        References(x => x.Employee).Column("EmployeeID").Cascade.None();
        References(x => x.Employment).Column("EmploymentID").Cascade.None();
        //References(x => x.Manager).Column("EmployeeID");
        //References(x => x.Supervisor).Column("EmployeeID");
    }

---

    public TrainingRouteMap()
    {
        Id(x => x.TrainingRouteID).GeneratedBy.Identity();
        Map(x => x.TrainingRouteDefinition);
        Map(x => x.TrainingRouteDescription);
        HasMany(x => x.TrainingCourses).KeyColumn("TrainingRouteID").Cascade.AllDeleteOrphan().Inverse();
    }

---

注意:我在 TrainingCourse 和 TrainingRoute 之间有另一个查询，它没有给出任何问题，甚至通过 TrainingCourse.TrainingRoute.x 模式访问属性。与这个的唯一区别是我也查询其他表。

Answer 1

TrainingRoute 是TrainingCourse(以及EvaluationHeads)的引用属性。因此，您还必须为此使用 JoinQueryOver 或 JoinAlias。下面我们将创建用于别名的虚拟对象(全部设置为空)。我们还拆分了查询的连接，因为它们会导致对新创建查询的引用

TrainingCourse trainingCourse = null;
TrainingRoute trainingRoute = null;
EvaluationHead evaluationHead = null;

var query = session.QueryOver<TrainingCourse>(() => trainingCourse);

// here we can work with criteria against the TrainingRoute
var referenceToTraingRouteQuery = query
    .JoinQueryOver<TrainingRoute>(p => p.TrainingRoute, () => trainingRoute);

// here we can filter the EvaluationHead collection
var referenceToEvaluationHeadQuery = query // here we start again from the base query
    .JoinQueryOver<EvaluationHead>(p => p.EvaluationHeads, () => evaluationHead)
    .Where(c => c.EvaluationHeadID == headId);

dto = query
    .SelectList(l => l
        .Select(() => trainingCourse.TrainingCourseDefn)
                     .WithAlias(() => d.TrainingCourseDefn)
        .Select(() => trainingCourse.IsAvailable)
                     .WithAlias(() => d.IsAvailable)

        // now let's used join alias
        .Select(() => trainingRoute.TrainingRouteDefinition)
                     .WithAlias(() => d.TrainingRouteDefinition))

     .TransformUsing(Transformers.AliasToBean<TrainingCourseDTO>())
     .List<TrainingCourseDTO>();

或者您可以使用 JoinAlias，在此处查看更多信息 16.4. Associations