在进行AVG时,NHibernate会转换为十进制

Question

我使用nhibernate 3与流畅的映射和MySQL5Dialect.我做分组并试图获得平均值:

var group = new TotalStatistic();
        SelectList(s => s
            .SelectGroup(t => t.RegistryName).WithAlias(() => group.Name)
            .SelectAvg(t => t.Value).WithAlias(() => group.Average))
            .TransformUsing(Transformers.AliasToBean<TotalStatistic>());

但它生成的sql查询包含强制转换为十进制,我只得到结果中的零,而不是像我想要的"0.0035".

SELECT ... avg(cast(this_.Value as DECIMAL)) as y1_ ...