的NHibernate的LINQ的GroupBy多個屬性不工作

Question

我使用NHibernate 3阿爾法2，我試圖做每月的職位數

這是我想出了

List<PostMonthFrequency> monthFrequencies = _postRepository 
    .FindAll() 
    //.ToList() //<- if included works. however not desired 
    .OrderByDescending(x => x.PublishedOn) 
    .GroupBy(x => new {x.PublishedOn.Year, x.PublishedOn.Month}) 
    .Select(post => new PostMonthFrequency { Month = new DateTime(post.Key.Year, post.Key.Month, 01), Freqency = post.Count() }).ToList(); 

代碼，請不是的FindAll將返回Session.Query（）

我還試圖刪除選擇

我得到的錯誤是：

NewExpression

完蛋了..我有其他的表達與選擇很好地工作，所以我不認爲這是，多與GROUPBY做事先

謝謝

PS我的臨時解決

List<PostMonthFrequency> monthFrequencies = _postRepository 
     .FindAll() 
     .Select(x => x.PublishedOn) 
     .ToList() 
     .GroupBy(x => new { x.Year, x.Month }) 
     .Select(post => new PostMonthFrequency { Month = new DateTime(post.Key.Year, post.Key.Month, 01), Frequency = post.Count() }) 
     .ToList(); 

Answer 1

張貼NHibernate的錯誤最好的地方是官方米列表here。