NHibernate Projections -如何投影集合

Question

我有一个场景，我只需要从一个实体中选择一个或几个列，但在一个查询中选择多个子列。我一直在尝试投影，但是在集合属性上得到了一个错误。这是一种正常的情况，但是找不到关于投影仅限集合的属性的信息。

Customer customerAlias = null;
Order orderAlias = null;
 var list = _session.QueryOver<Customer>(() => customerAlias)
                    .JoinAlias(x => x.Orders, () => orderAlias, JoinType.LeftOuterJoin)
                    .Select(
                       Projections.Property(() => customerAlias.Name),
                       Projections.Property(() => customerAlias.Orders))//this is the issue
                   .List<object>();

返回的错误为：

System.IndexOutOfRangeException : Index was outside the bounds of the array

Answer 1

在NH3.3中不能这样做。https://nhibernate.jira.com/browse/NH-3176

Answer 2

反转查询如何(假设订单有一个客户属性)：

var list = _session.QueryOver<Order>()
                .Select(
                   Projections.Property(o => o.Customer.Name),
                   Projections.Property(o => o.OrderProperty1),
                   Projections.Property(o => o.OrderProperty2)) // etc..
               .List<object[]>();