NHibernate用子查询计算另一个实体？

我有两个实体：

User { UserGuid, Address, . . . EmailCount // This is not a column in the database, // I just wanna get the count number from the UserEmail table // and map the value to this property } UserEmail { UserGuid, Timestamp } 

问题是如何通过NHibernate中的子查询获取电子邮件数量？

到目前为止，我有这个，但它不起作用。 任何的想法？

 User userEntity = null; var subQuery = QueryOver.Of() .Where(ue => ue.UserGuid == userEntity.UserGuid) .ToRowCountQuery(); return _session.StatefulSession.QueryOver(() => userEntity) .WithSubquery.WhereValue("EmailCount").Eq(subQuery) .List(); 

Answer 1

这将是如何使用subquery通过QueryOver语法获取内联计数的QueryOver ：

 User userEntity = null; var subQuery = QueryOver .Of() .Where(ue => ue.UserGuid == userEntity.UserGuid) .ToRowCountQuery(); var list = _session.StatefulSession .QueryOver(() => userEntity) .SelectList(projections => projections .Select(x => x.UserGuid) .WithAlias(() => userEntity.UserGuid) .Select(x => x.Address) .WithAlias(() => userEntity.Address) // any property to be selected ... // INLINE COUNT // our subquery placed into play .SelectSubQuery(subQuery) // this will populate virtual/not mapped EmailCount .WithAlias(() => userEntity.EmailCount) ) .TransformUsing(Transformers.AliasToBean()) //.Take(10).Skip(100) // paging .List();