NHibernate 对分组聚合支持的不好

Hibernate 对分组聚合支持的不好，例如下面的代码：

var query = from raqi in session.Query()
   group raqi by raqi.SpaceKey
   into g
   select new {
      g.Key,
      Count = g.Count(r => r.Raqi > 1)
   };

这样的查寻生成的Sql如下，很明显是错误的，

    select
        factstatra0_.[SpaceKey] as col_0_0_,
        cast(count(*) as INT) as col_1_0_ 
    from
        [dbo].[FactStatRaqi] factstatra0_ 
    group by
        factstatra0_.[SpaceKey]

LinqToSql可以生成正确的sql

-- Region Parameters
DECLARE @p0 Float SET @p0 = 1
-- EndRegion
SELECT [t1].[SpaceKey] AS [Key], (
    SELECT COUNT(*)
    FROM [FactStatRaqi] AS [t2]
    WHERE ([t2].[RAQI] > @p0) AND ([t1].[SpaceKey] = [t2].[SpaceKey])
    ) AS [Count]
FROM (
    SELECT [t0].[SpaceKey]
    FROM [FactStatRaqi] AS [t0]
    GROUP BY [t0].[SpaceKey]
    ) AS [t1]

看来，NH的Linq查寻还有很长的路要走。