lucene.net结合了多个过滤器并且没有搜索条件 [英] lucene.net combine multiple filters and no search terms

问题描述

如何在Lucene.Net的多个字段中进行过滤？在一个领域，我简单地做：

pre $ TermQuery工具=新的TermQuery（新术语（工具，钉子））;
Filter f = new QueryFilter（tool）;


如果我现在想要为过滤器添加指甲长度，我该怎么做？

另外，我希望用户能够在没有搜索条件的情况下进行搜索（即只需选择一个类别），我该怎么做？

解决方案

我想你问了两个问题... $ b

问题1：添加一个额外的过滤器

$ b 请记住， QueryFilter em> any 查询（不只是 TermQuery ）。因此，您可以创建要过滤的条件的 BooleanQuery 。

  TermQuery toolQuery =新的TermQuery（新术语（Tool，Nail））; 
 TermQuery nailLengthQuery =新的TermQuery（新术语（NailLength，3英寸））; 
 
 BooleanQuery filterQuery = new BooleanQuery（）; 
 filterQuery.add（toolQuery，BooleanClause.Occur.MUST）; 
 filterQuery.add（nailLengthQuery，BooleanClause.Occur.MUST）; 
 
过滤f = new QueryFilter（filterQuery）; 
  

问题2：不使用搜索字词搜索

如果用户没有提供搜索词，您可以使用 MatchAllDocsQuery 查询进行搜索。

How can I do a Filter across multiple fields in Lucene.Net? On one field I simply do:

TermQuery tool = new TermQuery(new Term("Tool", "Nail"));
Filter f = new QueryFilter(tool);

If I now wanted to add a nail length to the filter, how can I do that?

Also, I want the user to be a able to do a search with no search term (i.e. by just choosing a category) how can I do that?

解决方案

I think you're asking two questions...

Question 1: Adding an additional filter

Remember, QueryFilter accepts any query (not just TermQuery). Therefore, you can create a BooleanQuery of the criteria you wish to filter on.

TermQuery toolQuery = new TermQuery(new Term("Tool", "Nail"));
TermQuery nailLengthQuery = new TermQuery(new Term("NailLength", "3 inches"));

BooleanQuery filterQuery = new BooleanQuery();
filterQuery.add(toolQuery, BooleanClause.Occur.MUST);
filterQuery.add(nailLengthQuery, BooleanClause.Occur.MUST);

Filter f = new QueryFilter(filterQuery);

Question 2: Searching without a search term

If the user provides no search term, you can search using a MatchAllDocsQuery query.

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