NHibernate 标准查询对集合中的字段求和

发布于 2024-10-04 14:22:20 字数 737 浏览 2 评论 0原文

我在 Order 表和 Line 表之间有一个简单的一对多关系。

我想要一个报告每个 Order 实体和 Line.Value 字段总和的查询。

我可以在 HQL 中做到这一点：

select order, sum(line.Value) as LineValue 
from Order as order   
  join order.Lines as line
group by order

到目前为止，一切都很好。当我运行它时，我得到一个对象数组列表，其中 [0] 是顺序，[1] 是行值的总和。

如何使用标准 API 执行相同的操作？

我能得到的最接近的是：

session.CreateCriteria(typeof(Order))
  .CreateAlias("Lines", "l")
  .SetProjection(Projections.ProjectionList()
     .Add(Projections.GroupProperty("Id"))
     .Add(Projections.GroupProperty("Customer"))
     /* ... ditto for each Order field ... */
     .Add(Projections.Sum("l.Value"))

我必须手动添加我想要返回的订单的每个属性。如何指定要按所有订单字段进行分组？

原文

I have a simple one-to-many relationship between table Order and table Line.

I want a query that reports each Order entity and the sum of the Line.Value field.

I can do this in HQL:

select order, sum(line.Value) as LineValue 
from Order as order   
  join order.Lines as line
group by order

So far, so good. When I run this I get a List of object arrays where [0] is the Order and [1] is the sum of the line values.

How do I do the same thing with the criteria API?

The closest I can get is something like:

session.CreateCriteria(typeof(Order))
  .CreateAlias("Lines", "l")
  .SetProjection(Projections.ProjectionList()
     .Add(Projections.GroupProperty("Id"))
     .Add(Projections.GroupProperty("Customer"))
     /* ... ditto for each Order field ... */
     .Add(Projections.Sum("l.Value"))

I have to manually add each property off Order that I want to return. How do I specify that I want to group by all the Order fields?

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