如何使用NHibernate的条件api和实体查询子属性，以仅加载与谓词条件匹配的子属性 [英] How to query a subproperty with NHibernate’s criteria api and the entity to load only the subproperties matching a predicate condition

问题描述

假设以下内容:

public class Order
{
   public virtual int OrderId {get;set}
   public virtual ISet<Product> Products {get;set}
}

public class Product
{
   public virtual int ProductId {get;set}
   public virtual string ProductName {get;set}
}

您将如何使用条件api进行查询，以便仅返回具有特定订单ID的订单，并且其产品集合也应过滤到名称以字母L开头的产品?

How would you query using the criteria api so that only an order with a specific orderid is returned and its Product collection should also be filtered down to Products whose Name start with the lettter P?

推荐答案

我会使用DetachedCriteria来解决这个问题:

I would go about this with a DetachedCriteria:

DetachedCriteria crit = DetachedCriteria.For<Order>();

crit.Add(Restrictions.Eq("OrderId",orderID);
crit.CreateCriteria("Products","products");
crit.Add(Restrictions.Like("products.ProductName","P%");

crit.List();

然后执行条件并获得结果.

and then executing the criteria and getting the results.

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