查找子集合中不包含任何项目的所有项目 [英] Find all items where child collection doesn't contain an item

问题描述

给出:

public class Order
{
    public string Name {get;set;}
    public List<LineItem> LineItems {get; set;}
}

public class LineItem
{
   public string Product {get; set;}
   public int Quantity {get; set;}
}

我正试图弄清楚如何构造一个查询，该查询将返回所有没有包含商品名为"Apple"的LineItem的订单

I'm trying to figure out how to construct a query that will return all the Orders that don't have a LineItem with a Product called "Apple"

推荐答案

我已经考虑了一段时间.它出现了几次.问题在于Raven当前不处理！.Any()或.All()查询.

I've been thinking about this for awhile. It's come up a few times. The problem is that Raven doesn't currently handle !.Any() or .All() queries.

这个特殊的例子将问题简化了很多，以至于让我思考了一条不同的道路.我相信有解决方案.它需要针对静态索引的Lucene查询:

This particular example simplified the problem enough that it got me thinking down a different path. I believe there is a solution. It requires a lucene query against a static index:

public class Orders_ByProduct : AbstractIndexCreationTask<Order>
{
  public Orders_ByProduct()
  {
    Map = orders => from order in orders
                    select new
                    {
                        Product = order.LineItems.Select(x => x.Product)
                    };
  }
}

var ordersWithoutApple = session.Advanced
                                .LuceneQuery<Order, Orders_ByProduct>()
                                .Where("*:* AND -Product: Apple")

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