带有SelectList的NHibernate QueryOver

Question

我对一个表有多个查询。由于并非所有列/属性都是必需的，因此我将在选择列表的帮助下指定列。以以下方法为例。此方法有效

public IEnumerable<ResultDto> GetEntityAsDto(eStatusBinderProduktion fromState, eStatusBinderProduktion toState)
{
    EntityClass entityAlias = null;
    ResultDto resultAlias = null;

    var query = Session.QueryOver<EntityClass>(() => entityAlias)
      .Where(() => entityAlias.ProduktionStatus >= (byte)fromState)
      .And(() => entityAlias.ProduktionStatus <= (byte)toState);

    query.SelectList(list => list
         .Select(() => entityAlias.PrimaryID).WithAlias(() => resultAlias.PrimaryID)
         .Select(() => entityAlias.SecondaryID).WithAlias(() => resultAlias.SecondaryID)
         );

    return query.TransformUsing(Transformers.AliasToBean<ResultDto>())
          .List<ResultDto>();
}

由于我需要在多种方法中定义SelectList，因此我试图将SelectList移到单独的方法中。

以下代码不起作用，NHibernate引发异常

NHibernate.QueryException：'无法解析属性：MyProjectNamespace.DAL.Interfaces.Entities.EntityClass的entity.PrimaryID'“

public IEnumerable<ResultDto> GetEntityAsDto(eStatusBinderProduktion fromState, eStatusBinderProduktion toState)
{
    EntityClass entityAlias = null;
    ResultDto resultAlias = null;

    var query = Session.QueryOver<EntityClass>(() => entityAlias)
      .Where(() => entityAlias.ProduktionStatus >= (byte)fromState)
      .And(() => entityAlias.ProduktionStatus <= (byte)toState);

    MapPropertiesOfEntityToResult(entityAlias, resultAlias, query);

    return query.TransformUsing(Transformers.AliasToBean<ResultDto>())
          .List<ResultDto>();
}

private void MapPropertiesOfEntityToResult(EntityClass entity, ResultDto resultAlias, IQueryOver<EntityClass, EntityClass> query)
{
  query.SelectList(list => list
   .Select(() => entity.PrimaryID).WithAlias(() => resultAlias.PrimaryID)
   .Select(() => entity.SecondaryID).WithAlias(() => resultAlias.SecondaryID)
    );
}

附加信息：-映射正确-表格中填有测试数据

Answer 1

我们不需要别名来填充SelectList。我们可以从IQueryOver<TRoot,TSubType>附带的Type参数中受益：

//private void MapPropertiesOfEntityToResult(EntityClass entity
//   , ResultDto resultAlias, IQueryOver<EntityClass, EntityClass> query)
private void MapPropertiesOfEntityToResult( // no need for entity
      ResultDto resultAlias, IQueryOver<EntityClass, EntityClass> query)
{
  query.SelectList(list => list
   //.Select(() => entity.PrimaryID).WithAlias(() => resultAlias.PrimaryID)
   //.Select(() => entity.SecondaryID).WithAlias(() => resultAlias.SecondaryID)
   .Select(entity => entity.PrimaryID).WithAlias(() => resultAlias.PrimaryID)
   .Select(entity => entity.SecondaryID).WithAlias(() => resultAlias.SecondaryID)
    );
}

[entity现在是传递的Function的参数，并且其类型来自IQueryOver定义