NHibernate QueryOver与SelectList

debugcn 发表于 Dev

阿弗鲁

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>();
}

由于需要在多个方法中定义SelectList，因此我尝试将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
-表中填充了测试数据

拉迪姆·科勒

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

//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)
    );
}

在entity现在的传入的参数Function，其类型是从哪里来的IQueryOver定义

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