如何在NHibernate中为非分组列提供值?

时间:2010-03-17 13:06:45

标签: sql nhibernate group-by

我有一个标准查询:

Session.CreateCriteria<Sell043Report>()
  .SetProjection(.ProjectionList()
    .Add(LambdaProjection.GroupProperty<Sell043Report>(r => r.location))
    .Add(LambdaProjection.GroupProperty<Sell043Report>(r => r.agent))
    .Add(LambdaProjection.GroupProperty<Sell043Report>(r => r.cusip))
    .Add(LambdaProjection.GroupProperty<Sell043Report>(r => r.SettlementDate))
    .Add(LambdaProjection.GroupProperty<Sell043Report>(r => r.salePrice))
    .Add(LambdaProjection.GroupProperty<Sell043Report>(r => r.foreignFx))
    .Add(LambdaProjection.GroupProperty<Sell043Report>(r => r.batchNumber))
    .Add(LambdaProjection.GroupProperty<Sell043Report>(r => r.origSaleDate))
    .Add(LambdaProjection.GroupProperty<Sell043Report>(r => r.planName))
    .Add(LambdaProjection.GroupProperty<Sell043Report>(r => r.dateTimeAdded))
    .Add(LambdaProjection.Sum<Sell043Report>(r => r.shares))
    .Add(LambdaProjection.Sum<Sell043Report>(r => r.netMoney))
    .Add(LambdaProjection.Sum<Sell043Report>(r => r.grossMoney))
    .Add(LambdaProjection.Sum<Sell043Report>(r => r.taxWithheld))
    .Add(LambdaProjection.Sum<Sell043Report>(r => r.fees)))
  .List<Sell043Report>();

生成以下SQL:

SELECT 
  this_.location as y0_, 
  this_.agent as y1_, 
  this_.cusip as y2_, 
  this_.SettlementDate as y3_, 
  this_.salePrice as y4_, 
  this_.foreignFx as y5_, 
  this_.batchNumber as y6_, 
  this_.origSaleDate as y7_, 
  this_.planName as y8_, 
  this_.dateTimeAdded as y9_, 
  sum(this_.shares) as y10_, 
  sum(this_.netMoney) as y11_, 
  sum(this_.grossMoney) as y12_, 
  sum(this_.taxWithheld) as y13_,
  sum(this_.fees) as y14_ 
FROM 
  MIS_IPS_Sell043Report this_ 
GROUP BY
  this_.location,
  this_.agent,
  this_.cusip,
  this_.SettlementDate,
  this_.salePrice,
  this_.foreignFx,
  this_.batchNumber,
  this_.origSaleDate,
  this_.planName,
  this_.dateTimeAdded

然而,Sell043Report表有比SELECT语句中列出的列更多的列,所以我在尝试获取Sell043Reports列表时收到此错误:

System.ArgumentException: The value "System.Object[]" is not of type "xyz.Sell043Report" and cannot be used in this generic collection.

我怀疑问题是我没有为Sell043Report选择所有列,因此它不知道如何将数据集映射到对象。我正在努力实现这样的目标:

SELECT 
  this_.location as y0_, 
  this_.agent as y1_, 
  this_.cusip as y2_, 
  this_.SettlementDate as y3_, 
  this_.salePrice as y4_, 
  this_.foreignFx as y5_, 
  this_.batchNumber as y6_, 
  this_.origSaleDate as y7_, 
  this_.planName as y8_, 
  this_.dateTimeAdded as y9_, 
  sum(this_.shares) as y10_, 
  sum(this_.netMoney) as y11_, 
  sum(this_.grossMoney) as y12_, 
  sum(this_.taxWithheld) as y13_,
  sum(this_.fees) as y14_,
  '' as Address1,
  '' as Address2 // etc
FROM 
  MIS_IPS_Sell043Report this_ 
GROUP BY
  this_.location,
  this_.agent,
  this_.cusip,
  this_.SettlementDate,
  this_.salePrice,
  this_.foreignFx,
  this_.batchNumber,
  this_.origSaleDate,
  this_.planName,
  this_.dateTimeAdded

如何使用NHibernate执行此操作?

1 个答案:

答案 0 :(得分:3)

在调用.List&lt;&gt;():

之前,你可能想要这样的东西

SetResultTransformer(Transformers.AliasToBean(typeof运算(结果)))

其中Result是一个新类,用于存储所需的列子集。

另见这个问题:

Projections in NHibernate

您得到的错误是因为没有调用SetResultTransformer,它想要返回一个对象数组。然后(无意中)您尝试将该对象数组转换为Sell043Report对象列表,这是不可能的。

您的另一个选择是删除对List&lt;&gt;()的调用,而是处理对象数组。